Perhaps you didn't explain your intention to remain living with your mother long term AND crucially to do 50% of housework , cooking and gardening and DIY maintenance and pay 50% of absolutely everything (including the price of running a home long term - replacing things like fridge/ oven/ washing machine/ hoover / lawnmower as needed).
You really need to either be a fully invested equal co-tenant or to move out. You can't have it both ways (be on the rental contract but not fully pull 50% of the weight and hedge your bets about when you might move out).
As you and your mum argue so much and she isn't willing to treat you as an equal adult despite being 27 years old, you need to make a 12 month plan to be out of your mother's house by Christmas 2026.
Not being able to move out because you have some expenses to pay rather suggests that you aren't focusing on saving to move out though, despite having lived with your mother all your adult life.
Your mother sounds like a difficult, rather spiteful person BUT you must have been frittering money and/ or running up your credit card to genuinely not even be able to afford to move into a house share after so many years of living with your mum whilst working full time.
2026 is the year you save a rental deposit and move out.