It took me until my 50s to stop being self-conscious about my slender body and skinny arms. Exercising more helped a bit but it was mostly in my head. My advice - love yourself now! (The sign was for a Twitter pro-nudity campaign)
MtF26, 118lb, 5β6β. Iβve been on hormones for 18 months now. Iβm still insecure about a lot of things but Iβm happy that my body turned out the way I did.