Are you renting? If you are and the property is in your name, you have the right to remain in your home. This means you are responsible for making sure the rent is paid. If you're out of work like you said and you can’t pay your rent, your landlord may try and take steps to evict you. If you have a joint-tenancy agreement with your wife you may be able to negotiate with your landlord so that one of you can continue to live there after the tenancy runs out/marriage ends, though it will depend on the type of tenancy you have and what’s in the agreement. If you're on a mortgage and home is martial, then each party will receive at least some share of the equity. Also, neither party can sell it without the other's consent. If one party attempts to sell, the other can get a court order preventing the sale.

As for assets and liabilities, with marriage they are joint; that is, you are entitled to 50% of the net assets. Needless to say, you will need to declare your income plus savings, shares, etc. for the financial settlement.

Regarding your kids, decisions about who they should live with and what contact rights you or your wife has are based on your children’s best interests. But as you are the person who has been bringing up the kids, you're actually in a pretty good place. As a rule of thumb, you can expect to get 50% of the value of the joint assets (family home, etc.). And as you're on low income, you may even get maintenance payments from his wife. Any court worth a damn will take into consideration the fact that you has given up however many years of your career to bring up the kids.

This is an extremely TL;DR of UK divorce law, so you're better of seeing your solicitor (family lawyer, preferably) to seek more comprehensive legal advice and to go ahead with divorce proceedings, if you wish to do so. Remember: contrary to TRP belief, divorces are nearly as one-sided as some what have you believe.