How to stop being hyper sexual towards someone

I have a good friend online I play video games with (never met him) but I think he’s starting to become my FP and I’m trying soooo hard to not let this happen, but I kinda messed up and have sent him things. Especially when I drink it’s bad (which I struggle with) how do I stop from being so sexual with him when it’s literally all I can think about. I’m not usually like this so it’s odd for me. I don’t want to ruin our friendship.