My ex is trying to force me to sell

He finally agreed i could take his name off the morgage but only if im not aloud to sell the house untill our small children are 18. Then they would get half of the proceeds.

That's an interesting suggestion. In theory, his suggestion is not unreasonable. He says he is prepared to take his name off the deeds/mortgage without you having to give him anything but wants what he would legally be entitled to (50% or proceed) to go to his children when they turn 18.

However, what that 50% that he could claim would only be for time you bought the house together to the time he's taken his name off the deeds not 50% of the entirety of equity.

When did you purchase the property and who paid the deposit? The fact that he didn't pay the mortgage because he wasn't good with money is irrelevant, you were a couple and jointly responsible, so legally, he could claim 50% of equity build up until he moved out as a minimum (and possibly the deposit if he paid it in full).

If you work and could afford a mortgage to another property on you own that would accommodate the need of the children, then a judge could order the sale of the house and him getting his 50%.

The easiest way to resolve this is to agree the sum that he would be reasonable entitled to if you sold now, and then agree that when you sale the house, that sum goes into a trust fund for the children if you sale before they turn 18, or release to them when they are 18.

In the end, it's either him getting that sum at some point, or it going to your kids, so you might negotiate something that support the second suggestion.