I think that you hang in there. Sounds like you are over the hump. Give him the benefit of the doubt. You are going to have to let go of the past if you want to have a good future. Be glad that he has listened and really taken in the things that you have told him are a problem and that he is working to fix them. I think that he really cares about you and your feelings.
Besides ~ if you give up, you are going to have a whole new set of things to put up with. Step Moms, Step Dads, kids feeling that it is "their fault" that you divorced. You know that is what kids think even if you tell them that is not the case. Unless he is abusive, I think that divorce is not an option until the kids are grown and out of the house. Then you could re-assess your situation.
Anyways, I hope that helps you think about things a little bit - you have a big decision to make. Marriage is never a piece of cake, there are always going to be struggles, that is just life. But you hang in there and you give it all you've got. That is my opinion.....
One more thing: Love is not a feeling!! You say that you are not "in Love" with him anymore....what does that even mean? Do you expect to still get butterflies in your stomach? In my opinion that is lust, exitement of something new, etc.....Love is what you are doing when you accept someone the way they are flaws and all. Being "in Love" with someone is a choice you make. I get up and make a choice each day to love my husband (even on the days when he is un-lovable, cause lets face it, we all have our days when we are un-lovable), I flirt with him and act like his girlfriend, and it makes a big difference. I think as women, we have a lot more control than we realize. We set the tone of the family for the most part.