Honey, my heart is really breaking for you. I'm going to tell you something you already know you have to do. Leave him. Girl, you can live so much better with yourself. You are holding on to something you don't need. He is your albatross. Leave him. Now. Get a restraining order if he is abusive. Take your half. Good Lord, if you feel moved, you Sue him for your half of the savings that he blew. You sound like you have kids that need you (even though they are grown, they still need you). I don't think you will hurt them much if you do leave him, because sounds like they know him all too well. You raised kids and took care of him. Now it's time for you.
#1. Go to a local spa and get a new haircut, and color.
#2. Go shopping for new clothes.
#3. Go find the new you.
Join clubs. Go on group vacations with local social groups. Volunteer at shelters, or senior centers. I don't know if you work, but get a new job, maybe if you can. Sometimes when you work at travel agencies you get free trips. Be Social whenever you can.
It sounds easy, but I know its hard, but when you do find the new independant you, you will look back at the wasted years and shake your head. Don't worry about being "alone" in your older years. Would you rather be with someone who you knew didn't love you enough to respect you, or would you like to be on your death bed and smile because you made your life worth living, and known you were loved. Who knows, while you are out finding the new you, you just might find a new Mr. You and live happily ever after. Don't say you can't because you are scared that it is not what you are used to. That's a poor excuse, don't care about what the kids think. They have their own lives now, and it's time for you to have yours. Yes you can do it, and NO ONE is going to change your situation but YOU.
I hope you can find the courage to do what is best for you, and I hope that you find the happiness you so surely deserve.