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)
26M, 6'0", 205lbs - Have always struggled to see my body in a positive light and am still a virgin as a result. I've made some progress, but still have a ways to go.