Conflicted on whether to stick it out or let her go

Hi, my first post on the forum.

Im 44 years of age, divorsed now for 5 years who has equal parenting to my 12 year old daughter.

I have been in a relationship now for 4 years to a woman I met onlne.

She and her son moved in with me after 6 months and as a family, we functioned extremely well for 95% of the time.

We both came in with baggage of differing sorts, mine relating to my marriage and hers relating to a volatile upbringing concerning her parents.

We both function well together most of the time, however when conflict arose, things would go south rapidly. Unfortunately my partner has suffered with PMT and if conflict arose at the same time, the result would pretty well be inevitable.

Whilst I am the sort of person who is resilient and will take a battering before reacting, she would come out swinging (not literally), within seconds.

I do my best to take what she dishes out without reacting and for the most part, I succeed. There have been times where my limit gets reached and I fire back and Im ashamed to say, I can be hurtful.

I have been working on this and now can usually respond in a loving way, but damage has been done.

She moved out 12 months ago after an argument involving a insignificant lie being told between our children.

At the time of the incident, I knew how she would react and prompted her from the beginning to sort this with me as responsible parents. Instead, she blew up and accused my daughter of being the culprit and would have no part in actively dealing with the situation together, regardless of who was at fault.

Since then, although we live seperately, I still see them. Im expected to be the 'Dad' to her son, which is fine, but she will not have a bar of my daughter.

I cant raise the issue as it escalates and I am doing what I can to avoid this, so the way things are is that when I dont have my daughter, I am welcomed, but when I do, I cannot be with them.

As someone who is family orientated, being restricted like this is painful. My partner knows this but wont relent.

I am a aproactive sort of person who seeks out answers to problems and have done so in this case, but I cannot do anything to make my partner see how much I am hurting.

She recently had a minor breakdown, overworked, no time etc.

I have supported her in every possible way I can from financial support to meals, to offering virtually anything and I am getting nothing in return.

She will no longer say that she loves me, wont hold me, its like shes talking to a mate, not someone that means anything to her.

I cant bring it up as it is regarded as giving her more to deal with, so I simply try and deal with it myself.

Ive never handled rejection well, particularly from people I care for.

I can sense the effect its having one me, it feels like my tank is leaking faster than I can fill it.

I understand most would simply suggest I walk away and I can understand that, but from my point of view, there is no real reason for any of this. Every couple have their moments and most deal with them efectively. I just cant get her to buy into a responsible method to deal with conflict. Hers is to cut and run and Im left to work my butt of to mend things.

So the question is, do I stick this out or do I cut my loses and try again ?