Hopeless, let me first say, you are not hopeless. You are someone who is being treated unfairly by someone you chose to love and spend your life with. For whatever reason, he's unwilling to stand by his promises and deal with someone who for whatever reason he cannot seem to cut ties to. It could be sex, it could be that she's a rebel that writes bad checks, runs from the police and makes him feel that exciting, edge of your seat mentality. Who knows why he can't let go, but a part of me says 'who cares' what the reason is? Just the fact that he won't let go is enough to show that he doesn't care 'enough'. He may care for you, he may even love you, but he's not respecting you and he doesn't love you 'enough' to stop hurting you.
They say that when one door closes, another door opens.....it may be time for you to consider that there is still time for you to find someone who will be good to you and will be willing to love you in a way that is fulfilling and respectful to you. What he's doing is unacceptable, but if you allow him to continue the behavior, in a way, you are telling him that it's ok and that you accept it. You have to take stock of where you are and where you want to be in a year, two years, five years, 10 years and move from there.
Of course I'm here anytime you want to talk. You can feel free to ask for me by name anytime, it will be my pleasure to speak with you.