AIO my fiancé demanded we move in with his mother, but won't let my brother stay for a while, so I'm considering breaking up.

Throwaway account, my (25M) fiancé proposed to me (37F) last June after having dated for 3 years, we have a summer '26 wedding planned and everything about our relationship so far has been smooth sailing. My fiance, ill call him Mark, recently suggested whilst looking for our first house, that we move in with his mother.

Mark's mother, ill call her Glinda, had mark at 15, making her currently 41, only 4 years older than me. at first i thought it would be fine as i really loved mark and i truly believed that he was my soulmate, however as our relationship has progressed Glinda has made it very obvious that doesn't like me, making comments on my age and how im "not attractive enough to be such a cougar", her comments will often lead to fights where im always the one to apologise per mark's request.

Recently Glinda had surgery to remove a benign tumour, she is thankfully on track for a full recovery and only needs help with driving to appointments etc. However she has convinced mark that we must move in with her in her house, a good 45 min drive from my work. This was of course a hard no-go for me, if she was really sick it wouldn't be a question, but as she's almost fully independent and on track for a full recovery there is no need for us to move in with her.

Glinda must have manipulated Mark well as he threatened to call of the engagement calling me "cruel" and "selfish", so i agreed to temporarily move into his mothers home. there are 4 spare bedrooms and as my older brother (43M) is currently looking for a new apartment I offered for him to stay with us for a while. He moved in last weekend whilst Mark took Glinda to an appointment. I didn't think id have to ask them, as my brother has lived with me and Mark before, and now that i was living there, the house was now also mine.

When they got back, they both blew up at me yelling and screaming. Mark called me a Hag, bitch and a few other very hurtful names. since moving in with his mother weve been bickering and its been tense but nothing like this, it felt like he hated me. Ive been a wreck this past week, ive been sleeping in a separate bedroom than Mark and we haven't talked since, other than an argument here and there. I just feel so disrespected and betrayed that hes taken his mothers side over mine, to the point where im considering calling off the engagement or even breaking up entirely. I know that sounds dramatic but i feel as if it will always be a battle between me and him and his mommy, whose disliked me from the get go just because of my age.