Probably relevant life and body positivity tip from a sewist, pattern drafter and seamstress:
The clothes are the problem. Please try to remember that you are not the wrong shape, size or dimensions. If the shirt doesn't button closed the shirt is too narrow, you're not too wide. If the dress sags at the back it's the dress pattern, not your ass. Absolutely nobody makes clothes that are Actually Your Size unless you custom order or make them yourself. Even then fitting is a skill and an art!

You're not the problem, the clothes are.