Thank you for your question
My name is Clare
I shall do my best to help you but I need some further information first
How much are the assets worth and what debts are there
How much is the business worth?
Do you mean just £66?
What income do you each have?
Do you both work in the business - and can you continue to do so amicably?
Who will the children live with going forward?
How much does a cheaper three bedroom property in the same school area cost to buy
The starting point for division of the capital assets given the length of your marriage is 50/50 although it is possible that a court might award your a higher share - say 60% for the fact that you will have to have the care of the children until they are 18.
How that could be achieved would be a matter of negotiation between you using Family mediation if necessary
It is however the housing needs of the children which are the priority and if you cannot obtain his release from the current mortgage - and if a sale would not give you enough to purchase another property with a mortgage in your sole name then your ex would have to wait for his share until the youngest child is 18 or you cohabit.
I hope that this is of assistance - please ask if you need further details