Living a lie, obsessed and empty

I've been with my boyfriend for 2.5 years now. We've been through a lot together as we both have depressive illnesses. He is very paranoid and can be explosive, while I'm very guilty and sensitive. When I met him I felt so much, I feel like now I've exhausted everything I had of that nature in me. I say I love him, I imagine our future together. I don't want to imagine breaking up. But recently my head's been elsewhere. There was someone at work who seemed interested in me before. I don't know if they are still. But to start with it was kinda exciting, though I didn't think much of it. Now I get no pleasure from thinking about the situation,but I've somehow become obsessed with them. I post on an anonymous website hoping they see it, as I've read a post that matched exactly to a situation we were in one day and I thought it could be him posting about me. I go on facebook and scroll aimlessly, waiting for him to come online. but i never message him and rarely go on his page. i feel like my life is just waiting for these tiny interactions at work, which are so rare and underwhelming, i don't even really enjoy them or notice whenthey happen, i just look to the next one. i'm leaving soon and probably wont see him again. i think he wont talk to me as he knows i have a boyfriend now. i just don't want to leave and never know, though i know i could never show that i like him because i could never do that to my boyfriend. i'm torn.

Sadly you cant love two people. You can however feel love like feelings for multiple people. The only issue is that 90% of the time the last/most recent one is the one you are in love with. Talk to this "fantasy man". find out if he reciprocates. then you can either move on with your BF or throw time to the wind and have an adventure with this new man.