My girlfriend just decided not to talk to me.

Confused

I've been with my boyfriend for 5 years now and there's been talk of engagement, but i think i have feelings for someone else. About 3 years ago This other guy (i'll call him Bob just to give him a name) and I hung out a few times and really got along and the feelings sparked then and he felt the same way. Then my boyfriend found out before i could think about what was going on and ever since then he's hated me talking to Bob and has forbidden me to see him even though I'd already told him nothing was going to happen between me and Bob. So back to my dilemma, Bob has recently told me he still has feelings for me and i have realised that I still have feelings for him too. The problem is that we haven't seen each other since those times 3 years ago. Also, my boyfriend whom i am still with has no idea that Bob and I still feel for each other. And on top of that, i still care a great deal for my boyfriend.
What do i do?