Wipergreaser, antidepressants are pretty much the most weight gain promoting substance you can take (topped only by antipsychotics and the like). They are extremely anti-metabolic. It’s not really fair to blame it on the 180 diet, which of course can also cause weight gain but nothing compared to what you can get on antidepressants.
I will also note that a few people I know had mental health worsen while on antidepressents, and they are known to worsen depression in some cases, so I would mention all these symptoms to your psychiatrist.
I’ve noted before and will again now that medications are far more powerful than diet and no one should expect any of the methods here to make up for medication effects and side effects. As long as you are on the antidepressants, I think your concerns would be better addressed with your doctor rather than on these forums.