If you have a child with him, this could affect the situation. He is liable to pay 15% of income after tax, for the child, and you could try and claim spousal support, but if you're coping without that at the moment, it might be hard now to suddenly make a claim.
Your earning capabilities would be considered.
If you're still in the FMH, then you could stay there to meet yours and the childs housing needs. Your ex may not be able to sell it until the child reaches 18.
You'd be best by contacting the CSA, (or whatever it's called? I don't have dependent child, so no idea how that process works!) He does have to pay for the child, and the claim (I think?) starts from your application, I'm not sure you can backdate a claim though?
If you're on benefits, check to see if you can get legal aid to assist with the divorce proceedings, (assuming you both want one?)
A solicitor will best advise what Financial settlement you should be looking for. If he can't addord the child, how comes he can afford a house? You could argue to backdate monies owed come from a share of the house. The court could force a sale.
There is not a 50%-50% rule. It gets sorted through negotiation between the parties, (starting with a full financial disclosure of ALL assets!) negotiating through mediation, or if all else fails, then through a Court. (Last, and most expensive option!)
If he doesn't appeal against it, you should be able to divorce under 2yr seperation ruling.
There are no 'rules' in divorce. So no one can answer your 50%? question. You will get a financial settlement if he has the larger pot. He could argue short-term marriage, but you can argue costs for the child at least.