There is nothing particularly wrong with the way he thinks of things in as much as he wants you each to own 50% and he wants to split any house improvements 50/50- that’s the advice that would be given to anybody who is currently not married and not allowing any “cock lodging” or funding someone else.
The problem is though, these are conversations and agreements that should have been done before you bought this house and moved in together. For example he isn’t wrong to ask you to pay a higher % to “make up” for the extra deposit he put in as you have gone into the house 50/50 and he hasn’t ringfenced his deposit, so he is asking you to do this essentially to get you both back to “equal”. It’s not unreasonable in and of itself for him to want that, but that needed to be agreed with you before you proceeded with the purchase. He had other options available to him to protect his extra deposit for example ring fencing it, or splitting ownership differently so that he could have say 60% where you had 40%. At the point he didn’t want to take either option, you really needed to say “ok, well I’m not able financially to pay an extra % for x months”. It would have been preferable to sort that out before purchase as its pretty simple at that stage to select ownership % or ringfence deposit. Obviously that ship has sailed, but you can still sit him down and say “look, I can’t afford to keep paying x amount extra a month but I totally appreciate that you want to protect your extra contribution to the property, so we need to get a legal agreement which states you will receive £x extra in instance of sale, or we can get an agreement that you will be entitled to a higher %” for example.
In terms of house repairs etc, you need to sit down and get on the same page about it, again though, chats you really needed to have before buying the house. I totally agree that investing in your house is important and I love having a nice house, but I also totally agree with you that it’s not unreasonable to spend some money on meals out, drinks, self care etc. BUT you need to be on the same page. For example if our roof was falling down and urgently needed done, then yeah I wouldn’t be getting my hair and nails done or going out for a meal and drinks, I’d be putting every penny towards that urgent work, and so would my husband. BUT, if it was just that we wanted new carpets/flooring, I’d be saving towards it of course but I would also be happy to go get my nails done and go out for drinks because it is non-urgent, it’s just cosmetic. We are on the same page that for non-urgent work we’d rather wait an extra month for it and be able to have a date night, night out/meal, so you need to have that conversation.
As you’re not married he is again not unreasonable to want you to pay him back if he is going to pay for the roof upfront, it makes sense for him to pay if he has the money rather than put it on the credit card where you then pay interest, but it is his money and so I can see why he wants your half of it back asap so he isn’t out of pocket for too long. BUT again thats a negotiation for yous to have between yourselves, if you don’t want to have to prioritise paying him back and the roof absolutely cannot wait then you could suggest putting it all on your credit card or take a personal loan, he can then transfer you his half immediately so you can pay his chunk straight off and you can then just make monthly repayments for your side to your credit card/loan company.
So ultimately, you need a big conversation.
RE. Mortgage and deposit, if you cannot keep paying the extra amount then that’s fair enough, but he is not unreasonable to want to protect the extra he put in. Meaning you need to sort something whereby his extra bit is protected legally and then you just pay the mortgage 50/50.
RE. Work done, you need to have a big chat between you about that. Can you agree that for non-urgent work, you’d both prefer to wait a bit longer and be able to spend on treats/nights out? He’s not unreasonable to not want to pay for the entire thing and then not get the money back for years and years, but equally you can’t be expected to prioritise that debt if you have others. Meaning that you need an alternative, so maybe the compromise is waiting to have work done (if thats possible) so you can save for it first which you’d be more easily able to do if you were just paying half of the mortgage, or for urgent repairs you look to take out a loan or a credit card and he can then pay off his chunk immediately if that is what he wants to do, whereas you are then free to just make the monthly repayments to the separate company without owing him anything.