What would be a fair settlement ? Advice Please

Hi I would appriciate it if someone could give me their advice on what would be a fair settlement.

The situation is as follows:

Ages: Me 40 He 37

2 Children aged 6 & 7 (Living with me)

Lived together for 6yrs Married for 2.5yrs been seperated for 1 yr

My income £21,000 (including benefits)per year
His Income £42,000 per year

Joint mortgage, house worth 128,000 outstanding mortgage 112,500 so about 15,500 equity.

Pension Me:0 Him: don't know but he pays about £175 per month into it.

Neither of us have any savings or assets. No liabilites.

He is currently living in the FMH. I moved out with the children because he wouldn't.

He wants to keep the FMH so if he does what would be a fair settlement?

Thanks for reading and hopefully you can give me some advice.

1. If he wants to keep the house he's got to get you released from the mortgage. On his income that may just be possible.
2. He will have to raise a lump sum to help you fit out a new home and he may struggle with this. You will need to produce a budget for the new home and what you need to kit it out.
3. Pensions are of very limited relevance in these circumstances.
4. Once he is paying child maintenance, that's probably as much as he can afford.