Hi June, I can understand that it must be really painful for you right now. And you trusted him in a way, right? And thought after your last experiences that at least this time.........?
But you know he really isn't worth all you're going through right now- no-one is!! You're worth so much more than all of this!!
And if he wasn't the guy that you thought he was, then that's a fault with him why should you have to all of this fallout for something he wasn't?? Just give yourself real credit for seeing that he was wrong for you, putting yourself first and deciding to walk away. Some people would find it really hard to do that. And now you need to keep on putting yourself first just as you did right then. You showed real strength there make it count!!
As for having to keep seeing him, well you can try to keep as much distance physically and emotionally from him, but remember he lost out at the end of the day, right? You were willing to put so much into the relationship/did put so much in inc. emotionally but he just didn't make the grade, right? His loss!!
Now focus on you, you deserve to be feeling so much better than you have. Think about being kind to yourself, give yourself a break, and try to move on to thinking/doing things that will help you.
As for falling for the wrong people (I'm sure a lot of us have done that despite there being signs) although maybe there have been more/different signs for this latest relationship that you can learn from to protect yourself a bit more in the future. Call it a learning experience on the road to finding someone really right for you.
And sometimes there may not be any signs or no significant signs that people are wrong for us when we're getting to know them, but if you keep going with the recognition of when they come up and keep on putting yourself first then you're doing a great job. And you're getting that one step further to finding someone who's really, truly the person for you.
Best wishes
Alison