Sorry if this is long don't know what to do for best. Was with ex DH for 10 years married for just two. Found out I was pregnant soon after we married and we were TTC so DS now 4 was planned. Not long after DS born exDH started being awful to me, ignoring me and went on holiday with a group of friends including a few single ladies. He went on lots of lads nights out. To cut a long story short he cheated with at least three women, ended up in an affair with a woman he worked with. Tried to throw me and DS out and in the end for ease we moved in with my parents as couldn't face him. He set up home with OW and they've now had a baby. He used to have DS every weekend then moved it to EOW now once a week. Has never paid maintainance claims he had nothing but holidays a lot. OW confronted me told me I had to go back to marital name and change surname of "my runt" (DS) to my maiden name! It's on his BC! I went mad and we had as you can imagine a huge fallout.
Now DS not allowed to stay overnight with his dad the OW won't allow it. I wanted DS to have a relationship with his dad but honestly his dad is barely interested but when he sees him (2 hours a week and sometimes cancels) it's all over Facebook like he's dad of the year. I asked exDH for financial help for nursery he said no but been on two holidays in the last year.
At the end of my tether what can I do?