What should I do? Walk away or keep trying?

I'm not sure what to do and maybe a stranger's perspective can help. I have been married now for almost Six years to a guy that has not been truthful from the start of our marriage. Over the years I have loved this guy deeply and have bailed him out of trouble too many times to speak of but its his past that keeps causing trouble in our marriage and the fact that each year something from his past rears its ugly head. He lied about child support he owes, unpaid parking/speeding tickets, and even about a child he had before we met. I am perplexed as to why this man can't step up and be a man (he's over 40) I'm constantly having to bail him out, have the same conversation regarding his past but the most hurtful thing was the kid. It's not that I mind he has a kid from another woman, but he's denied him parental guidance....doesn't pay child support for him and basically denies his existence. Now I understand everyone makes mistakes, but he seems like he never makes amends for his and it makes me tired and angry because of what he does to this 14 yr old boy and I had to force him to pay the other kids' child support. To add to this burden, I found my first love again who is divorced and we have talked so much about this situation and my life. I guess I'm looking for someone to slap some sense into me...my two oldest kids hate my husband...all my friends thinks he's a Schmuck. He hates for me to go out by myself but when I take him with me to friends house he acts like a jack ***..very unsociable. See I'm a fixer by nature and I'm thinking if I don't ditch this guy, he'll ruin me and cause me to be bitter. This is my third marriage and it really sucks because no counseling in the world can fix a liar and make the hurt disappear. This guy works but he's always costing me money...seriously and he never brings in anywhere close to what I do (financially) and it shouldn't matter as long as he's contributing but it does. You know how some people are just unequally yolked? I also have a lot of feelings for my first love and even if he decides to stay in my life or not I believe this person I am married to will be the death of me. So, is it time to give up and walk away while I'm still sane even though I should hate this guy for all the lies and pain he has caused me? I mean my grown kids hate him, his own kids and family hate him....I'm so confused.