Need help framing the ends of my Cattle Panel greenhouse.

Hello everyone. I was hoping to get some advice, video links, or other resources to help frame the ends of my cattle panel greenhouse. I've posted a Youtube video below that shows the current state of the structure. I figured a way to attached the panels using electrical cable clips instead of timber staples, which I was excited about. I was also really happy that I could attached the plastic while the panels laid flat on the ground. I was able to square-up the plastic really well and pull it nice and tight. I used wiggle wire channel on one side and poly-channel on the other side to hold the film in place.

I'm just struggling right now trying to figure how to frame the ends. I'd like to continue using the Vericom Clips if possible. I bought some 1x2 furring strips to experiment with. Lumber is so expensive now that I can only afford to use the smallest wood stock possible. If price were not a consideration, I'd just use 2x4 and plywood but that is not happening. Any advice is appreciated. Cheers!

Edible Acres made several and has multiple videos on it: