Sex is wack ever since I don't trust him anymore

I used to enjoy sex with my bf he was the sweetest man I have never met in my life but after a misunderstanding we had on whether he was cheating or not I stopped trusting him and the feeling I used to have when he graba me, kisses me or touch me just disappear. I wanna talk to him bout it but I m afraid he will take it the wrong way or withdraw from me what can I do?