Hello

Sorry to hear about your hair. You might have cut it when Moon was in Aquarius or Pisces, these are the worst moon phases to cut the hair.
Look into Olaplex hair care, it's expensive but is proven to strengthen and repair hair. I haven't used it but have read real-life experiences with it, it sounds really good. If you can't afford it then the next-best is said to be L'Oreal Bond Repair, although they were sued for stealing Olaplex's patented formula. And buy a wooden hair brush/comb, not metal or plastic.
Trim your hair when Moon is in Capricorn, Taurus, or Virgo to improve the structure of your hair. Waning Moon will make it grow slower but stronger, waxing Moon will make it grow faster but might be a bit weak unless it's cut in Earth signs. The day of the week doesn't matter, just aim for those Moon phases.
I most recently cut my hair when it was waning Capricorn Moon and I see a difference after a few months, it's definitely healthier than it was before. Capricorn itself rules the basic structure of the hair, while Venus rules the beauty of it, so when Venus goes direct it will be strong in Pisces which will be good to begin new things to improve your hair. And then perhaps don't trim it when Venus is in Aries, and then trim it again when Venus enters Taurus, these dates are in our Calendar