Thanks for your replies, mooby88, I don’t see this as a long term solution, it may end up working but my focus for now is being there for the kids and supporting my ex (stills feels odd referring to her that way) whilst deals with her fathers illness. Once he has passed she will need time to grieve and the kids will need stability.
Irrespective of the fact she has hurt me I still care about her, she is still my best friend, it would help if I was on the same page as her emotionally and hopefully soon I will be there. We have divided up the week so we each have time for ourselves and I am starting to rebuild my social life and find my confidence, hopefully through this I will find some happiness and start to move on.