Why is she like this!!????

Hi ladies

I need some serious support from ladies in similar situation or who understand this. I have such a love hate relationship with my Mum. She’s a typical axial mother she tried to raise us in the best way and tried to be friendly but along the way she takes me her older daughter as granted in comparison to my younger brother and sister. I am happily married and I love mum but I can’t visit her for longer than couple of hours otherwise we either argue and have difference of opinions or she seriously hurts me without realising she’s hurt me. I have been TTC for awhile and really hoped this month was my month as I had all the symptoms but unfortunately a week late and started and came with vengeance. Extremely heavy heavy flow, excruciating pain and feeling dizzy I’m barely able to move. Been bed bound all day, my mum knows that but instead she treated me like I’ve got a common cold and when I told her I’m not feeling well she gave me a cold look and said I’ve got cold too I’m not complaining! I feel like cos I’m

The eldest and obedient she takes advantage of me and takes me for granted walks over me. It’s not like that with my brother or sister though. If my sister is in same position she gets taken care of her every need. If my brother is feeling low she will go out of her way to look after him. She loves me but unintentionally she always hurts me because she doesn’t realise that she has never treated me the same as her other two kids she’s always told me to

Suck it up or act mature. I can’t handle her partiality at times it breaks me inside. I can’t talk to no one about this. I need advice guys.