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)
40(f) - 130lbs - 5ft 7. The older I get the more I accept my body for what it is. This body has produced 2 kids, every sag and stretch mark is worth it. normal is beautiful