My friends and family say forget it...get yourself together and love yourself and your kids and to forget about being with her and move on.
I would suggest modifying this advice.
Yes get yourself together/ Yes Love yourself and your kids. Put her and your relationship away in a box and put the box on a shelf somewhere. Move Forward not on!
Be the best DAD you can be.
Are you getting access to your kids? If not have you seen a lawyer?