I've been dealing with this a bit over the past few years, though mostly due to (A) being pregnant, (B) Being postpartum, and/or (C) being sleep-deprived.
Pregnancy made me tired, foggy-headed, emotional and dizzy. None of which are useful for making decisions. Postpartum hormones made me literally drop things to run and grab a crying baby. Even if said baby was being taken care of by someone else, I couldn't stand to hear them cry--I had to HOLD them, and my brain wouldn't function until I was. I also had postpartum depression for much of that time, and that sure didn't help things! And, I've been sleep deprived most of the past 4 years, too. Last night, for instance, my daugher had a stuffy nose and woke me up--I'm not kidding-- every 5 to 20 minutes, all night long. I didn't sleep for more than 20 minutes at any time. My brain's not at full-capacity right now!
When my brain/emotions are compromised like that, I don't make any decisions unless I've had days to think/feel about them. It might be useful, if your brain keeps changing it's mind on things, to have a decision journal: "Today I thought about getting a ______. Here's why I thought it was a good idea. Today I thought I
should move my sheep to this acre, here's why I thought it was a good idea. Today I thought so and so was a
jerk, and here's why." The next day you might think of all new things, that might be totally oposite. Write them down! I know when I'm really tired/emotional/depressed, I
cannot remember what life is like when I'm not depressed. I can't think back and access those other mental states. That's why journals are so great. They help jog that memory and emotional response so you can analyze what happened when you're out of the situation, and hopefully make a bit more reasoned response. Having things written down also helps with the mental fog. It's hard to hold all those pros and cons in your mind when your vitamin deficient/tired. Writing things down frees up that "working memory" to consider the pros and cons, rather than that "working memory" being all used up just trying to
remember those pros and cons!
I also find it helpful to only make decisions--if I can help it--when I have no distractions. I.E. the kids are asleep, the house is "clean" (i.e. all the evening chores are done), etc.
I hope things get better for you soon! I hate when our brains/emotions don't operate at full capacity!