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)
Not a great angle (my arms are only so long) or flattering pic but I like locker room nudes because I feel great and my confidence is boosted after a good run/workout. Lost another few pounds and still working on the belly but I’m ok with the progress.