Hi Latavia,
First of all, welcome to the HealingWell depression forum. You have come to a very good place where people will give you their honest view on things and not judge you.
The first thing that I would recommend is counseling. Not necessarily marriage counseling, but individual counseling. That way you will have an impartial view of things and be able to make the right decision. You will also be able to come up with a plan for your future.
I am not saying that what you are doing is necessarily wrong, but you should always think of your children's best interest first. Make sure that if you do leave, that they will be well taken care of. Whether that be with him or you.
I am sorry that you are not in love with your husband. But make sure that you aren't confusing lust with love. Make sure that you aren't going with this other man because he just makes you feel good about yourself and gives you attention. If you leave, leave for you, not for him.
It is no fun being in an unhappy relationship. I know that. But remember the children, know what is best for them. But don't sacrafice your happiness over it. You have a lot of thinking to do. And look at this realistically. Are you going to be happy alone? Are your kids going to be well taken care of? Discuss this with a professional counselor and get the answers. Many times the grass looks greener on the other side, and make sure that this isn't the case. Other than not being in love with your husband, do you love him? Is it going to be worth the hurt that you are going to cause him and your children? Does he know how you feel? Take it all into consideration and think this through carefully before you make a move. Make sure you are not just infactuated with this other guy. And like I say, when and if you leave, do it alone. Don't put him in your plans. Then later if you want to try a relationship with the new guy, you will be stronger.
I hope that this all works out for you. I do not think you are a bad person for doing this. But make sure that the situation is what is depressing you, not that the depression is causing the situation.
Best wishes for you, keep posting.
Hugs, Karen