Family Opinions on Self Harm?

Hi there, I'm MenheraBunny.
I've been an active self harmer for about 8 years now, obviously I look a mess, everybody knows about it by this point because realistically it's way too hard to hide, but about how people reacted... sometimes I hear people saying that you should tell somebody- when I looked at the internet as a 16 year old and found out you are meant to tell someone, I did. It was one of the hardest things I ever had to do.
and one of my biggest regrets in the end.
because not there's nothing left to the imagination.
Everybody has found out about it plenty of times while I was doing it. They sort of think I've stopped now? Which I sort of have because it's summer? I can stop for weeks or months at a time, and it gets stored up and used to amplify once I start up again. They don't really think I've stopped, they couldn't because they know I still do it. They're sort of beyond caring, but they never really had a reaction to the problem in the first place if that makes sense? They've just sort of always known, and already acted pretty neutral to the while thing. Except one time my grandparents stole some of my blades and gave them back like a week later :/ that was a pretty crappy thing to do.
I was in hospital for it just after mum and I ran away, I had to have a surgery which has happened before, but this is the first time I had to get actually put under and the whole deal.
There doesn't seem to be any other things I can do to cope.
Sometimes we will have a fight and I'll be in my room crying, they'll be yelling at me and my grandpa will be the only one who stops to think, and goes 'okay well don't do anything 'stupid' to yourself now will you..?' I don't bother to lie, I tell them straight up, ' of course I will, that's what I do, now will you please leave me alone' and they will tell me not to and I won't do it for that night or day, but they never really... it's just not a big deal to anybody. It's never been a big deal, just seen in a bit of a petty light (unless my nan gets me to wear a nice dress, then it's a big problem because I would be so pretty apparently without them)

I'm not sure how to treat it. I have always seen it as my own thing that nobody knows about, but now it's my own thing that people know about but it doesn't really change anything. It's still mine. It's still... people being aware doesn't really scare you out of doing it. It doesn't make a difference so it will probably always be there. I don't know how else to look at it. If nobody else takes it seriously, how could I possibly take it seriously.