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)
So theres an obnoxiously bright floodlight in the corner of my living room for some reason (rental) but it makes for great posing practice. 28, 5'9", 230lbs