I had many chance but couldn't do it.. Pleease help?

Hi there, im 18 year old gay guy and well i had about three propositions to have well .., and i turned all of them down because i only have this is so embarring ... 5 inches and im really embarred to let any guy see it, i mean i once saw a 13 year old guy who had a bigger one than me... and it really makes me feel bad... should i just go for it?. what if they laugh?