Antidepressant weight gain?

Hi everyone! About a year and a half ago I started to take Zoloft, I’m on 50 mg and I’ve gained 20 pounds. I’m not overweight but I’m worried because it’s a big difference (went from 110 to 130, I’m 5’4). I do Lagree 5x a week, I track my macros, and at this point am even seeing a dietician. There’s been no “cheating,” no bad diet, nothing, and I got my labs done and had absolute perfect insulin, hormone, and vitamin levels.

I’m just confused because I’ve never gained this much weight, and I’ve teetered between 110-120 most of my adolescence (I’m 26F).

I tried Wellbutrin when I brought up this concern but it had really poor effects on me. I stopped after 3 months and having a complete mental breakdown on it.

If anyone has any advice, please give it. Maybe something I haven’t heard before. Zoloft saved my life, so it would be hard for me to stop.