Seeking Guidance

I made this account just for this post. I don’t even know how to start. Basically I (18M) love my cousin (18F), she is my 1st cousin once removed, and she’s so pretty. Our relationship isn’t bad, but we aren’t super close. She’s got a bf and she is an athlete, but she posts on her instagram and she looks amazing, her figure, her looks, everything. But I could never admit how I feel and I could never have her, basically how do I get rid of these thoughts