Honestly OP, unless there is domestic violence at play here you would be absolutely stupid to divorce him now.
I know MN loves nothing more than to bear witness to the breakdown of a marriage, to tell women that they will be so much happier without him, how the children will be happier growing up in a house without him etc etc, but the reality is far far different.
You’ve only been married for two years.
DH paid most of the deposit for the house.
You weren’t earning when you got married, so time as a SAHM isn’t going to be taken into account, you won’t be given credit for the fact that you decided to give up work which enabled him to further his career, you already weren’t working, and although the children are both of yours they were born prior to marriage and as such if you’d split before being a SAHM would have made 0 difference.
Spousal maintenance is no longer a thing, or at the very least it is extremely rare for it to be granted, similarly mesher orders.
Any equity you’re given will count against you if you’re applying for universal credit, similarly if you put money towards a house you won’t be entitled to housing benefit.
You’ll need to go back to work as you won’t be able to afford to live on UC alone, and at that point you’ll have to shed out several thousand a month for childcare given the number of kids you have.
And being a single parent is lonely. Forget meeting someone else with three kids you have permanent residency of, forget having a social life at all in fact.
Just after having a baby is not the right time to be making such earth shattering decisions, not unless you absolutely have to.