Am I a scumbag, for not settling for what he's offering

[Elizabethstongue]

It's a long one, and very outing. But I don't know anyone who's gone through a divorce and need advice please.
Husband left in October. Married just under 4 years, together 10. I have DS 15 from a previous relationship. He's raised him as his own. We have a mortgage on a house together, tenants in common. I'm still in the house, H paying full mortgage, won't take half off of me as 'it's his mortgage' (not that I could afford it anyway)
In November he wanted to discuss the house. He wants to buy me out, but only pay me half the equity minus the legal fees and stamp duty. He thinks the deposit we put into it is his and he's being generous in giving me half the equity. I said I deserve more as I helped with that deposit and he made a comment that the bank wouldn't let him borrow more than half the equity. So I'm guessing he only wants to give me that as its the easiest way for him.
His GP gifted us 20k towards deposit.
We saved a further 13k for deposit, and then had roughly 6k on legal fees and stamp duty.
He is saying HE saved that money. But I was paying for other things and bills so that he could put the money aside in savings. We was married whilst we saved for the house if that's relevant. And married when his GPs gifted us the money.
When speaking about the house, I said I would have to think about what he had proposed and discuss it and he said if you get legal advice I will make sure I get a better solicitor than you and you will come away with nothing.
We tried councelling after this but he has decided he no longer wants to continue the marriage.
He is living rent free in a friend's spare room.
He has called me this evening to discuss the house again. I have said I want to sell and split 50/ 50 and if he has any savings I won't go after them. He has called me a scumbag and all other names under the sun for suggesting this.
Aibu? What would you think I would be entitled to after a short marriage? And no children together? Am I a scumbag for wanting more than he is offering?

In the course of a 10 year relationship, that includes a gift of 20k to both of you. If that was in the context of your marriage, morally I think it's yours just as much as his.

You say he saved the deposit while you paid the bills.

Does he have other savings that you have enabled? Because they should be included too.

OP, when my marriage with 3 children broke down I offered my stbx to go 50/50 on equity in house, value of joint business and pensions. He refused and raved at me calling me far worse than scum bag. I just wanted to settle it between ourselves and stay friendly for children sake but I learned no matter how reasonable you want to be if your stbx is not reasonable there is nothing for it but getting a good solicitor. He was deliberately obstructive refusing to fill out forms and not turning up at court etc. Eventually judge said if he did not attend next date she would make judgements in his absence. I ended up with 70 percent equity in house, 1/3 of his pension as pension shared and half of joint business (I already owned 50 Perce of shares). After judge made this pronouncement in court, he then tried to back peddle and ask for 50 percent which is what I had asked for in first place. He should just be reasonable to begin with instead he caused pain for me and kids we never can forget. Your DH is doing the same. Get legal support. Don't tell him untill you have had time to think about your options. I would deduct money his GP gave him and ask for 50/50 on rest.

What is the actual £ figure for the amount you are disagreeing over?

You sound grabby to me OP. You contributed less to the deposit and he is giving you half of the equity? Why would you be entitled to more than half?

Just as a word of warning but if he is currently h paying the mortgage and your living there then you could end up owing him occupational rent for his half of the property.

The obvious compromise seems to be he keeps his grandparents money and then what’s left is split 50/50