Oh wow sounds like you really have tried just about everything already!
I do think for you medicine is definitely the best next step since you’ve already tried so much else and, like you said, sometimes it really is just chemicals!
For me, I think my thing is more just anxiety and maybe a bit of seasonal stuff, so the talking helps, especially since I’ve never really had that before, but I know it won’t help everybody and for some people, medicine is definitely the best, or sometimes the only, option. Which is perfectly fine! Definitely nothing to be ashamed or afraid of or anything. I know not everything works for everyone so I say if you want to try medicine then go for it!
I wouldn’t be worried about the weight gain or anything. I think you will be fine. It affects everybody differently so you might not even experience it. And even if you do, they can likely try different medicines and/or dosages until they find the right one for you.
I really, truly hope that you are able to find something that works for you.