Hiding feelings

Hi there! first time poster here and I thought I would ask for some advice (I think this is the right place to do it...)Anyway, I have some rather close friends who I talk with a lot and I guess I grew a crush on one of these friends... i'm almost certain he is 100% straight and not interested in a relationship with a guy. I've been feeling like this for a few months now (about 6-7) and can't take the pounding in my chest when I talk to them or the constant need for their attention.Now my question...Should I just let it be and deal with it until it hopefully passes? Would me admitting this to them have any chance of ruining our friendship? Should I admit this to them at all?I have absolutely no idea what to do with this...Apologies if this is posted a lot but I wanted to ask for some personal answers. Thank you! :D