I wasnt totally on my own for the 5 years - I did date a bit and not long after my divorce I had one longer relationship which I ended because I wasn't ready, and rather than in the past thinking I had done major issue, I recognized that a) the guy was going faster than I felt comfortable with and he was so headstrong personality-wise I felt we weren't that compatible anyway and b) I knew I had to prove to myself I could do it on my own (being a lone parent) and be happy on my own ( which I have been
).
It was after that I decided to do the real work sorting myself out, and the various romantic interludes that happened have only helped with the learning process, I think.
Unfortunately a few months ago, after finally feeling ready and thinking I'd found someone lovely, I've just been on the receiving end of exactly the same - he's bolted and won't even speak to me 
He never knew his Dad, who left when he was a small baby and was also recently separated so quite clearly I should have seen this coming a mile off!
Another lesson for me learned 
I'm so pleased you're talking to you DP Peppa. If only mine would talk I could explain about how I know how it feels and we might be able to work something out. It was never going to be a rushed affair as it was an LDR with DC on both sides. In fact recently I'd said "let's relax and enjoy it but I do need consistency & commitment to what we are doing now" (he was doing the hot/cold thing).
But somehow it seemed one minute he needed it to be 100 mile an hour steam train (plans for the future, where we could live, what we'd do re work, who would cook and who would wash up once we moved in together, etc) and the next he'd be gone off to some unreachable place either physically or metaphorically.
I hope your DP understands. I think if you want it to work you've got to do your bit by seeing it as he probably does, which is "this relationship is for ever unless something really problematic crops up" rather than "this is ok for now but I know it's going to end at some point" - which makes you then think "crap it might as well be now" when you feel under too much pressure, and start to feel the need to run.
Believing the "this is forever unless..." statement means you can take your time, you really can. You've got the rest of your lives
Just need to work with your dp on finding a pace that suits you both, and be committed to it, for his sake.
If you really can't believe the "this is for ever unless..." statement now, it would be kinder all round to bail, I think.