SLIMO talk:
Ma best Vino, There's nothing wrong with still having feelings for him - you know him better than his past does. All people regret things of the past - so regardless of what happened, forgiveness will end the constant reminder of "past". Don't fall into the trap of attachment though - believing that your life depends on him - that isn't loving, it is just demands and expectations. Attachment is often a result of love: love is honoring a sense of well-being for yourself and others, while attachment is the idea that something is required (conditioned, as opposed to unconditioned love). The only thing that is causing you the emotional stress is what you are telling yourself with your own thoughts. If you are telling yourself that you "need" something, then you will believe it. If you recognize that the concepts in your mind about who the guy is do not define you or your life, and that your life situation with him do not define you at all, and have no bearing on your life, you will be much happier.
It's the concepts of the "past", which come from memory, that make you feel depressed. Because you have been telling yourself that you want what you are thinking about in your mind, you have been wasting energy trying to reach a mirage (the thoughts are like a mirage).
Take a deep breath and allow the worries and doubts to drift by like clouds, and just watch the clouds in amusement without attaching to them.
If you would like to continue a relationship with him, you could just tell him whatever is the most honest thing to say. You could say that you don't care about his past, and that it's the present him that you enjoy so much. Maybe ask him to be honest about whether there's been anybody else, but if you do that make sure you ask him in a way where he feels welcome to be honest about it - make him feel like it won't hurt you to hear the truth, because if anything will stop him from being honest it's because he doesn't want you to be hurt.
I wish you a happy life, just remember that there is never anything that you need in order to be happy!
miss you Vino, you know I'm still here anytime you need to talk ;))