Should i tell him how i truly feel or keep it to myslef?

Ok so theres this guy who i might have fallen head over heels in love with. the thing is we are good friends who have a ual relationship with each other but i think i might have took it too far. he always tells that he doesnt want a relationship but everytime i try to stop talking to him all together he comes out of no where and makes me laugh and there we are talking again. i dont know what to do anymore. i really want to tell him how i feel but im also scared cause i know i will just be setting myself up for heartache. and i have tired to get over him i just cant get my mind off of him every second of the day i catch myslef thinking about him no matter where i am or what i am doing. i need help what should i do??