If you get a chance read some books on co-dependency. You might find them helpful.
Let's suppose your husband has changed, met the woman of his life and is going to find eternal happiness.....
Are you going to let that stop your life? You didn't have the greatest marriage. He wasn't a great husband. You hung on in hope. Why not find someone who thinks you are the greatest gift on this earth? Why not find a guy who wants to be special for you. Let your husband go.... in all those years he couldn't be a great husband. Heck he was a pot head and a lousy provider for his family! I know you say you love him, but gosh there's soooooo much better out there!!!!!! You aren't losing anything great.
Even if he's "great" for her, he wasn't great with you. Let him go and move on with your life.
Yes, I know that's easier said than done and it's incredibly painful. But you can do it.
There is no arriving, ever. It is all a continual becoming.