why am i blowing up so fast when im active person?

i work at a school as a yard duty... i have 2 kids 3 years old and 1 years old. i have the stupid nexaplon birth control shot (im thinking that this birth control is making me gain weight) im not even eating a lot though... i been dealing with anxiety and stress and depression so im eating less but i feel myself blowing up and getting fatter my stomachs never went down after birth of my kids. my legs are big and arms.. 😫💔💔 what am i doing wrong ? what do i need to do to lose weight ..: