I'm sorry your parents are unsupportive in any regards. It sucks when you can't find comfort/support at home. Since you haven't really specified your question I'm not quite sure which part of non-supportive family you'd like advice on. However, coming from a background myself where parents didn't want to help me out with anything I'll drop a few tips below.
A lot of the time your parents or a parent still loves you. They just dont know how to show it. Similarly, dont value your worth on how much you parents seem to value you.
When you dont get support at home, you often need to turn elsewhere
Academically, speak to your teachers. If you're comfortable explain your situation and they will often provide extra support (Lunchtime, Emails, Extra work etc etc). Also speak to your Guidance/Pastoral teacher if you are comfortable as they can often make deadline exceptions etc if you are really struggling.
If your parents are getting in the way of you going to things like college or university the key is to speak to as many resources as possible. Often there will be bursaries and scholarships available you should look at. You can also get general funding depending on your course/country. At the end of the day though, if its finance thats the problem, you just have to get a job. I know it sucks at a younger age when all your friends go out and you have to work to support yourself but it's worth it in the long run and its the reality.
If its emotionally, rely on your friends. Explain your situation and let them be there for you. Make friends in loads of areas so you have a lot of people to just chat to when you feel isolated. Join clubs, societies, volunteering etc etc.
If its with your sexuality, this is a hard one. You are valuable and you are allowed to feel however you do. Sometimes your parents may change their minds and come round to your way of thinking. Other times they wont but that doesn't decrease your worth, Its difficult to accept that your parents don't accept a part of you but again, focus on your friends, teachers, tutors, work colleagues, youth workers and you will learn to live with it.
Same with mental health. You have to just be more independent and do things on your own. Go to the GP. Get the help. Don't let your parents get in the way.
Overall, just learn to have confidence in yourself and love yourself. Build strong relationships with those around you and you never know, one day your parents may change!
Sorry this is super long but you didn't specify!!!
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