@KAYlett
Plenty of good advice from others about things needing to change for you and ideas for stepping back.
It might be hard, but I hope you manage to implement some of these ideas and things improve for you. When setting your new boundaries, remember not to give in to pressure from others! And keep trying even if you find it hard, as it should get easier with time.
In response to your comments above about finding what makes you happy, try and ask yourself these questions and see if that sparks anything (no need to write answers to them on MN if you don’t want to - totally up to you).
Think back to your childhood, can you remember anything from then that you enjoyed? Did you have a favourite lesson at school? Did you enjoy a certain sport or hobby or club?
Was there anything from secondary school that you really liked/that made you happy? Any extracurricular activities or trips? Any assemblies that fascinated you? Any lessons/hobbies/clubs? Any subjects you were keen to do at O Level or beyond?
Is there anything that makes your heart sing?
Any films you’ve always loved? Any TV shows etc. that you enjoy/used to enjoy? Any concerts, theatre shows or comedians you’d love to see?
Any holidays you used to dream of doing (whether you haven’t yet fulfilled that dream, or maybe you did the holiday ages ago and would love to go again).
There’s lots of questions above and I feel like it’s best to gently probe your own mind. It could well take a while to feel that you know yourself better, but any steps you take is progress in the right direction!
Are there any community groups, clubs or projects you’d enjoy getting involved with? I imagine having something just for you, even just once a week could really help you feel like you’re a higher priority and feel more worthwhile. Just a few suggestions: any exercise classes, Pilates/yoga/Tai Chi, gym session, swimming, aqua aerobics, cycling, walking groups, gardening group, art club/class, sewing/knitting/crochet group, book group (like in a local library), board games group, religious group etc. so many options! Anything that made you think ‘hmm I think I’d like that’ or ‘maybe I could try that’?
If you love helping others, what about any local volunteering you could do? There’s probably lots of places that would appreciate your help much more than your family do!! E.g. charity shops, local museum/animal charity/nature reserve, National Trust/local historical attraction, tourist attraction, volunteering in the day centre of a local branch of a national charity etc.