My (28f) boyfriend (34m) claims our shared home isn’t mine

I’m looking for advice on what is the most equitable way or how others in relationships split living expenses?

My(28f) bf (33m) purchased a house years ago before I was in the picture. At the time he was married and had a child with his ex-wife.

He purchased the house entirely in his name due to her credit and has countinued to own it after they separated. He is a retired vet and receives a monthly disability check from the VA that is about equal to my salary.

As we were dating I started to search for a house to purchase… my budget was limited so I didn’t have a lot of great prospects so I was doing it rather slowly but still actively looking.

As we got more serious he really pushed for me to just move in with him especially since he had his daughter. I was hesitant but eventually did. I’ve countinued to actively search for a house to purchase and save towards a down payment. I’ve lived here paying half the rent + utilities + most of the groceries for the last year.

The other day during a board game my partner and I were debating (in what seemed initially friendly) about the meaning of a rule. At which point he stated abruptly and aggressively. That his name was on the mortgage and this was his house, so what he says goes and he decided the way the rule of the game played out.

This threw me off and made me feel horrible. Like somehow tho wasn’t our house and my portion of bills was discounted. That was over a week ago.

Today the conversation of common law came up and in him explaining it to his daughter it led to us talking about the home and how things got divided up if we stayed together that long.

Regardless of the how- he states that my payment barely contribute to the mortgage and only cover utilities. I pay half of the cost of living + groceries for all 3 of us. Frankly, I pay more than I view are my fair share and feel splitting the cost of the two bedroom home down the middle leaves me paying for a room I never get to use that his daughters lives in. Reading step parent blogs they pay based on the number of rooms. Plus my grocery bill has tripled living here. I feel I’m footing the bill for a lot of his daughters living expenses.

Which makes me feel resentful when every moment he drives home that I don’t contribute or have any stake in this home.

He’s right that I have no stake but I more than contribute with household costs and chores… but if I moved out on my own our relationship would end. So it feels well silly.

I want to revisit how expenses are split, because I don’t feel secure in the way he’s talking that I won’t be left out to rot. I am much better at managing my money and even with a higher cost of rent living alone I was able to save more money living on my own. And since he keeps making it so clear this isn’t my home and I don’t contribute I frankly want to focus on saving more and finish purchasing my own home. Really … I want to leave this home and relationship.

How do you split expenses? What would be equitable in our situation?