I will preface this with: I am at least 99% sure I'm the asshole.

My ex wife and I separated last June. In January I started seeing someone new, got on well with her, plenty of shared interests.

Last week I broke up with her for what I think are shitty reasons: 

She has no financial security, we are both 40, she has no pension, low pay job, no savings, previously bankrupt. 

She was a bit too keen, declaring herself in love after a couple of weeks, making comments about moving in with me.

And lastly, I fear my ex wife would use me moving on to try limit my access to our children (when, a few months ago, I mentioned I was messaging someone I met she straight up said she didn't think I should see my kids of I was seeing someone else. This despite the fact she has moved on with someone else) and I can't afford to go through the courts to get access

Tl;dr I broke up with someone for shitty reasons