I don't know if this could help. Please, consider that I am not a professional and my advices might be wrong for your case. I can say some of this stuff worked for me.
SPEECHING
1. Understand that you can learn and master any skill. If you are good at them at the beginning then you will have a smoother start. If you aren't good at them, then the start is rougher but you can achieve the same. Sometimes we don't bother with skills we are not good at since they have an opportunity cost, but sometimes we need to learn the skills. Even deaf and mute people can speak, using signs if they have to. Dislexic people can't read long texts, but you only need some guiding words if you know the score.
2. Do you remember how you learned your current set of skills? Did you succeed from the beginning? No. It's always a process of try, fail, recognize what you did wrong and try again. And it is almost always a progressively difficulty task. If you are learning to cook, you don't start trying a
lasagna, it's boiled eggs.
3. Now you want to learn the speech skill. You have some difficulties (shyness, dislexia) that make you start a bit more difficult, but you can do it. Speech is the
art of communicating an idea, you need an audience to check how well your message is being understood. If you talk to a camera, you don't have this feedback. Pick some easy audience (wife, friends, tell them you need their help) and some easy topics, then practice speech with them Tell them you need to practice. Ask them to be honest and provide feedback. If you don't find people willing to help, maybe take a course.
4. If you want to really get good at it, then you need to read subtle reactions since many people aren't honest even when you ask them to be. This is a problem with all social interactions: people aren't honest because they all want to look like nice people. They usually don't want you to feel bad or they don't want to be portrayed as the annoying guy who goes criticising everyone else, so they won't tell what you did wrong. But if you look attentively at their bodies and faces, you will notice different expressions. Pay attention to them. At first you will not know what they mean, but keep noticing them and you'll find out eventually if you are not autistic.
5. Once you think you have learned enough from your easier audience, increase the difficulty and try speaking to a larger audience, maybe two or three friends together. Keep increasing difficulty in small steps until you think you can handle harder tasks. When talking to different people, you will notice that some reactions are common no matter who the audience is. Other reactions depend on the background of the people you talk to.
6. Talking to a camera or a recorder you don't have the immediate feedback of your audience, but if you have practiced it before you can remember how it usually goes. Here is when the advice of 'imagine that you are talking to (...)" works. If the recording is for kids, then you have to imagine that you are talking to a kid and remember how kids react to your speech. You don't get the feedback, but you imagine that you are getting it so you don't block yourself.
SHYNESS
You mentioned you are a shy person, so maybe it's a good idea to work a little bit on this aspect.
Shyness comes from lack of confidence, it's a fear that you will fail and people will not accept you. Being rejected from society is a real threat, but shy people overdo it. Some people don't care about what others think or are only slightly worried and they can ignore the fact that they are exposing themselves to the others when speaking or recording their words. Shy people can't ignore this. I can't order you to stop thinking about it, you can't stop thinking about the blue elephant if I mention it to you.
So I think the best strategy in this case is to build up self-confidence and view yourself in a more balanced way. Drinking alcohol is a cheap and fast, but risky, way of building confidence. Specific therapy could work in the long term without relying to drugs.
I'll start doing some introspection. Relax for 5-10 minutes or do some meditation to get in the mood. You need to meditate on your answers for some personal questions. By this I mean to try to find facts and reasons to prove that your answer is wrong, find alternative answers and try to prove them wrong too, until you find one that has little to object. So make yourself some of these questions without rushing
the answer, meditate on them properly, take your time, 30-60 minutes, one line per session, things like:
- 5 things I dislike about my personality: Have they some redeeming qualities? Do I want to change them? What can I do to change them?
- When I see this bad characteristics in another person, would they make me to not accept this person? How many people will accept me if they knew this facets of me? Are they things to be ashamed or is it just me who dislike it? Are they common defaults or are they exclusively mine?
- 5 things I like about my personality. Are they to be admired or is it just me who likes them? Are they common traits? Do I want to let people know of my virtues? Why?
- Do I need to be accepted by people? None at all, only some people, everyone? Why? Examine your answer.
You can figure yourself out more questions of the like. Or you can try different questions from the beginning if you feel so. Don't be mistaken, this is hard work. After every session, let it sink for the rest of the day and a sleep, before trying the next line of questions. This introspective work that may take a few days or weeks is just so you know yourself a little better. To walk from point A to B you need to know where point A is. Once you have a solid ground and have acknowledged whether your shyness is excessive and it is hurting you, you can proceed to treat it. I think there are two topics to work on: self-confidence and caring about opinion of others. You are probably overweighting the bad aspects which make you to not trust in your social abilities or the consequences of not being accepted, but that's because you are focusing too much on this aspects of your reality.
There's a technique called active awareness where you dedicate a few minutes every day to find for specific things around you and meditate on the process. For example, you can one day for several minutes look for things with a soft surface, another day you can look for things with a triangle shape, another day you can look for things that make noise. When you get the hang of it, you can project this skill to be aware of some characteristics of your personality that you were underevaluating. For example, let's say that you think of yourself to be very egotistic. Then, for one or several days, you try to be aware of everything you do that is not egotistic. You don't have to force these actions, only to be aware when you naturally do them. You will realize that you are not so (insert default here) as you initially thought. There's a saying, 'you become what you observe', so by not focusing on your bad aspects you are influencing yourself to be more balanced.
But it could be that even with a more realistic vision of yourself, you still want to do things for changing. Here you could challenge yourself, set some doable goals, and track your success. That's the same when you want to lose weight. Commit yourself to not eat (insert unhealthy stuff here) on working days for at least three weeks. Three weeks is the time we need to stablish new habits. If it works, set a new harder challenge, If it doesn't, set an easier goal. You need to get in the mood of achieving your goals so you can be positive about doing them.
I don't know how hard is your shyness, but a very simple goal could be to just say hello to one stranger every day. Or talking about your feelings with some friend (it's polite to hear their feelings in response). Maybe say to your family that you love them.