Caring for my grandparents.

I wish I could offer some helpful advice, but my heart goes out to you.

If you are a carer, you are entitled to a Carer's Assessment if you are living in the UK. Ring your local Adult Services and ask for this to be done. They will help you make decisions about the care you give, they will ensure you are receiving the right benefits and help with respite care to give you time for yourself.
I have been in your position with my mother and it is so wearing. She has just gone into a home and it is like a weight has lifted from my shoulders. Don't get me wrong, there is also a deep grief that I couldn't go on and every time I visit her I get flack which hurts but the day to day grind coupled with abuse has diminished enough for me to see light at the end of the tunnel.
At the end of the day, nobody has the right to demand you care for them. You can help them get care and offer ways forward to keep them safe but there is not an absolute right to expect that from anybody. Sometimes counselling can give you the tools to stand back but the one thing that you have to keep in your mind is that if they wear you down, you won't be any good to them anyway.
Maybe the first thing you should do is talk to Rape Crisis of how to get help to process your feelings. It is you absolute right to take time for that. Virtual hugs heading your way.

Oh you poor thing. This situation needs to be resolved quickly. I suggest you get Social Services involved. It is not your responsibility to care for your grandparents, you should be out in the world and working, and enjoying your life at thirty years old. Where are your parents in all of this? It sounds as if they’ve abdicated their responsibilities. Please get help from Social Services quickly and stop these caring responsibilities quickly so you can get on with your own life.

You should never have been put in this situation at 10 years old. It sounds like you have given more than enough, you have your own life to lead and must start putting yourself first. That will be difficult as you've been in this situation since childhood and it will be ingrained in you to look after them. It also sounds as though the oldies are taking you for granted which is very wrong because they owe you so much. You don't say how old they are or whether they have special medical needs. As others have said, get help and don't give up until you do.

Forgive me, but this sounds a little unlikely.

GSM, yes the usual spelling/grammar blips etc. Just in case it's genuine, though, Sjw1992 contact Citizens advice or Social Services.