Boy Troubles

A few months ago I was hella crushing on my friend Sam and I knew he liked me back but I kinda talked myself out of it. Then this older boy Trevor came into the picture and he’s a very sweet guy and I found out he really really liked me so me being stupid decided to take a chance on him when he asked me out. And things have gotten really serious between us but I can’t help but think about what if I went with Sam instead and how I really still like Sam still. But as soon as I started dating Trevor Sam got himself another girl. And I know this is all me being really stupid and I should’ve gone with my heart in the first place and I don’t want to ruin things for Sam now especially since he seems really happy with this girl. And Trevor is head over heels with me and treats me really well most of the time. Like I do love Trevor but I feel only 75% in it. So do I see what happens with Trevor and let things take its course or do I break up with him and tell Sam how I really feel or do I just break up with Trevor and stay mum about everything with Sam and wait and see what happens with him and his girlfriend?