mortgage/ex partner/no guarantor - HELP!

[miss]

Me and my ex partner have a joint mortgage and still live in the same house paying equal halves of the bills even though we are separated.
We do not have negative equity but are struggling to sell the house.
He keeps trying to force me to rent the property out, so that we can both leave, but i do not want somebody else living in my house, plus he wants to cut corners and not tell the mortgage company or get the proper insurance - which i am very unhappy about.

To come up with other solutions I have looked into buying him out, but upon phoning my mortgage company they have told me they will not lend to me soley, so i cannot take his name off the mortgage.
I cannot get a guarantor either as my father is too old.

I havent spoken to my solicitor yet, but does anybody know if a seperation agreement could be drawn up, to
1 - pay him out an agreed figure
2 - keep his name on the mortgage until i got sorted out, but he would not be entitled to any of the profits after he got his settlement figure?

Or does anybody else know of any other way I could still keep the house pay him a settlement fee and get rid of him!!!

x