I’m trying to lose 40 pounds... help

So recently, I got off of my nexplanon because I gained about 50 pounds in 1 year. Since getting off of it, I lost about 5 pounds but again feel like i’m still gaining and gaining. I don’t know how else to stop. I’ve tried dieting, exercising, intermittent fasting, you name it and i’ve done it. I don’t know how to motivate myself anymore.

Everyday I find a new stretch mark in places ive never had them before. I hate how I look in pictures, and i’ve become a homebody because im just so ashamed.

Can anyone give me any advice on what to do? I feel like i’m helpless at this point. Any advice on motivation, exercising, or next steps are welcome. I’m considering going to a doctor at this point to ask them what to do.

(I’m about 240 rn and would like to get back to my normal 200)