Welcome to the forums. This is a safe place to chat, express and vent.
Firstly congrats on completing year 12. Hopefully you'll get the results you desire to further your education and the career of your choice.
I bet you are as confused as hell right now. And scared too no doubt. Just know you are not alone.
If you are not ready for the whole world to know, that's ok. Your folks will keep it secret too. They are there to support you and love you. Talk to them, tell them that. I know it's not easy.
I'm 47 and came out to my wife of 20 years just 6 months ago, after deep depression that almost cost me everything. I wish I had done it when I was 17.
Talking about something as deeply personal as this is one of the hardest things ever done, but you'll pull through it. If I can at my age and being married, no doubt you can too.
You know your folks love you and don't care. If keeping it quiet for now is what you want then that's ok, but at least you have now shared that one big secret. The hardest part is done.
If you need to talk to someone, their is a peer support line called Qlife. Google them. Just someone who doesnt know you that you can talk to.
I thought I'd never share my secret, but it is now out there.
I've never explored it, and my wife is the only relationship I've ever had. Even knowing that I was gay since I was 12, I still haven't fully accepted it, but am now coming to terms with it, and I now know I will be ok.
Don't stress about never having a relationship, it will all come with time. Just take a breath, and pause, reset your mind.
Maybe you don't like talking about your feelings, but speaking to a counselor will do wonders. Qlife can recommend a LGBT counselor near you.
Post as much as you like here, this community will support as much as you need.
We are here for you if you need it.