hi, im a  16 year old ftm.

im really skinny, ive small arms and legs, and im small chested.

I have a problem which is any weight I gain goes to my thighs/arse, which are really fat in comparison. I hate it, and running or biking has done nothing to help, and I am extremely uncomfortable to go out unless im in school uniform because only the jacket hides it. its spring here and my parents recently moved me to a stupid really hot city, so I cant wear layers outside like where I used to live.

what the hell do I do

You can't really control where weight goes when you gain it, just like you can't target specific areas of the body for weight loss. Testosterone enables a lot of people to redistribute their body fat in a more male way, but it is one of the more long term effects.

Aside from trying to not gain weight, the only surefire way to remove specific fat deposits is liposuction unfortunately. I'd say figure out how much you need to be eating, don't exceed that amount, and make sure you're working out if your current fat distribution bothers you.

This is the best I've got. I hope it helps:

https://www.susans.org/2015/02/28/suzis-seven-surefire-weight-control-tips/

cheers