Hi I need some advice

So back in 2007 when I was heavily pregnant with our first child I discovered that my partners flat at the time was about to be repossessed by the bank for about 14K in arrears

My partner who does mortgage brokering ( unlicensed ) talked to me about ‘ selling the house to me’ for £ 240,000 to prevent the bank from repossessing it , he took care of all the technical details of the transfer and all I did was sign documents , I put no money down for anything and inherited an interest only mortgage ( stupid in hind sight)

I didn’t realise at the time that he put a charge on the property for £15000 on the flat .

In the preceding months he did not pay a penny into the mortgage , I had a very low income job as a clerk in local council and my wages could not cover living costs , mortgage and child care so I quit my job and went on income support for about 8 months .

I also insisted that we move out of the house and rent it so that the rent would cover the mortgage and he would be forced to do some constructive work to pay the rent where we would live. We ended up not paying the landlord who took us to court and was awarded £ 20000

13 years on the money owed to the bank stand at £ 255000 , there is a charge on the property of £15000 ( partner ) and a second charge ( £ 20000) but the property has appreciated a bit in price .

My partner is currently fighting in court to have the second charge dropped

We are now on the verge of separation so planning to sell the flat . Partner insists that he is entitled to 65% of the proceeds of the sale and he will remove his £15000 charge

What should I do ?