Nope. You need to raise a case with CMS, which will cost you £20. They will ask him for a range of payslips to verify his income, and then they will calculate what maintenance he must pay you. If he refuses to supply payslips, they will go directly to HMRC to ascertain his salary. If he doesn't pay, they will hound him until he does. They can arrest his wages and even confiscate his driving licence for non-payment.
You will need a separation agreement, to divide up all assets of the marriage. You need a good solicitor for this, you really do. You can get half his pension (monetary equivalent). You can also get a chunk of money for "economic recompense" because you sacrificed a career to care for the children and he did not (so he needs to pay you for that).
If you do sell the house, the calculation may look like this:
House sale £200k
Repay mortgage of £120k, so £80k cash left.
His Pension pot at present = £50k Yours = £0, so he owes you £25k
So, you get £40k for house sale + £25k for his Pension = £65k for you.
He gets £40k - £25k he pays you for Pension, so he gets = £15k
Plus whatever you agree (if anything) for economic recompense.
You get the Child Benefit (always goes to Mother)
Plus Child Maintenance.
If he lets you stay in the family home, it's likely he can force a sale when the youngest is 18.