Madeline, you need to figure out what to do about your current boyfriend before you think about any other boy.
Personally, I think that extreme jealousy and questioning your every move is a deal breaker. No matter how 'nice' a guy is, this type of behaviour is unacceptable. But that's just me.
So anyway, decide if you are to stay or go with your current boyfriend based on the relationship you have with him. If you stay, then forget the other lad and give your relationship all you can. If you decide to leave, then feel free to pursue anyone you like. But the new guy should not have any bearing on whether or not you end the relationship or not.
Never regret anything that has happened in your life. It cannot be changed, forgotten or undone. So, take it as a lesson learned and move on.