If she has as much money as you suggest, and if you've always with her agreement been the SAHD, then your lawyer should be able to file for whatever the UK analog for child support and transitional alimony is. The court will look to the children's best interest. Losing their primary caregiver won't be in their best interest, and a court can order that the more financially secure spouse support the other so that that result doesn't happen.
I get the feeling you don't fully grasp your legal rights. It will make you feel better to get that understanding. From there, you can build on a strong(er) emotional base. It will understandably be hard to make self-improvements if you're worried about a roof over your head, losing your children, etc.
Me: 46 W: 44 Married: 17 Together 21 D13; S10 BD: 03.03.15 (Not attracted to you) Almost 2 years trying, alone, to save marriage Status now: Divorced (effective 06.13.17)