I hate my body and want to gain weight😩help

So to start off I use to be on depo, I was a size 14, had DD breasts, thick thighs and a large booty I use to exercise a lot too so I was muscle bound in quite a few areas.. I weighed around 170-176 lbs.. well fast forward I got off depo, started loosing weight and then I went through a breakup, started drinking very heavily, not eating, a few things happened at a party that shouldn’t have.. my arms and legs are no longer muscle bound I look like a stick figure, my big ole booty looks like a waffle, flat with dimples, my boobies have went from a DD to barely even a D and are saggy.. I’m 155 lbs and wear a size 9-11.. I’m really self conscious over it considering I’m only 23, I use to love my body and now I hate everything about it..

do you ladies have any tips on how to gain weight? Or exercises to help gain weight?

Also, I no longer drink.. I haven’t had alcohol in around 7 months.. thanks in advance for the advice..