Difficult mother relationship

(I apologize in advance for my medium english, Im from France but I find it better to post in another language )

Hello,

Im Selma (18yo) and Ive a difficult relationship with my mother, but I'm not sure wether I should make more effort or if the fault is 100% on her side. I know that in Islam we are forever indebted to our mother but maybe at some point there are limits ? Im really not sure that's why Im posting it here lmao.

So to begin, I have a little brother wich is 2 years younger, our parents divorced when I was 10 and they thought it better for us to live with our mother and visit our dad on week-ends, wich was perfectly fine. ( note that my mother converted when marrying my dad, she still bought us halal food but along with my dad never really prayed and she stopped carring much at some point about eating halal ) Then when I was about 13yo, my mom remarried a man, she never properly introduced us to him and he first was "a friend that needed a home to sleep for a few weeks", but then weeks turned into months and the man slept with my mom so it was obvious it was more than a friend. Then out of the blue she told us she was pregnant from already some months before we met the man. When we started to live with him I didnt tried to make friends because I dont like the presence of men it makes me uncomfy, and even after my mom told me she was pregnant he never made big efforts.
I learned later that he was not earning a lot, his job beeing theater and slam shows, my mom was basically working for 3 while beeing pregnant. She also was doing all the chores and me and my brother were helping a little but she was very stressed and yelled at me and my brother every evening, when we did our chores it was not enough, when we did an effort we couldve do more, and my step-father was just sitting in a couch watching and asking for food.
Beeing yelled at everyday, + other stuff at school, I had a depression and it makes things worse, I hated everyone in my home and my only breaks were on week-ends when I could meet my dad and dad's family which wernt yelling. My brother was also affected but I wasnt talking much to him as I was stressed enough and he was doing classic teasing brother stuff. I knew he was also affected tho and my mom could be extremly mean to him as he started to gain weight, she treated him as the cliché "geek" even tho he was just 4 kilos "too much".
When covid came, it was just too much so we took our stuff and got to our aunt's. We then learned that our mom gave us aïd money in secret, and then started to understand our step-dad was telling her to yell at us and other things we couldnt notice ( I also heard him yell at her to tell us stuff but didnt take notice of it at first ). We were taught by our mom that everything we bought was too much money spent, while they bought themselve 2 cars and desigual jackets, but for us 40 euro shoes were too much money, even though at each begining of school the state gives for helping money 1000euros for me and my brother in total.
Then my aunt went to explain with us to my mom that we wernt comfortable maybe because of our stepdad and that we wanted to live with our dad, our stepdad listened from afar saying nothing, but when we were about to leave he stormed out yelling on my aunt and us, after the conversation was just turning around we leaved. Things were heated for a while, my mom gave us our stuff by throwing it without warning on the streets, passerby stole a little bit and she never gave me my bookcase and desk crafted by my grandpa, remember I told you she was pregnant, my stepfather refused to let us see our 2 little sisters for a while, until we saw the judge and settled it. My brother had a very hard time forgiving my mom and didnt wanted to see her much of the time when she didnt brought our sisters, and he cried a lot saying he thinks our mom hates him. When she learned about that, she just said "its not my fault, if its pressing him he should see a psychologist".

After everything calmed down, we tried to go sleep at our mom's a little but we realised that it was very dirty, triggering our dust allergies, even after our mom cleaned we couldnt sleep there too much. Plus our stepdad just looks at us with a mean looks. We now see our sisters once every weeks or every two weeks, and I know this could repeat with them.
Even tho my mom did all this stuff, I know she isnt mentally well (she lived a difficult divorce of her parents) and she is trying her best, she genuinly isnt a bad person, but still since then its not the same at all. She seems to give us attention only out of guilt, and even tho I try to make efforts I always find myself sending more messages to my aunt or grandma than my actual mom.

I'm sorry for the big text I wanted to be precise, because I really want to forgive my mother deep down but I dont know if I would completly forgive her as my brother but also my dad suffered a lot from that, but I know it might be all because she was manipulated by a man and I should do more efforts ? I'm very confused thats why I wrote here if I can get any advice.

Thank you for reading