I'm scared that my family will find out, if they do, what should I do?
Tricky to answer:
Be prepared - don't do anything stupid to begin with. Have the door locked, hide anything suspicious really really really well, encrypt your data, encrypt your phone, use reasonable passwords, clear the internet history and cookies every time you close the browser, use do-not-track and use every option to opt-out of advertisement cookies, don't put it on facebook (etc), use a VPN and encrypt your data stream and so on. Otherwise your internet provider and the NSA definitely know. IT-security, data sparseness, obfuscation and opsec up the ass. Check everything of that triple-twice.
Speaking of which, If your family sees you with a dog cock up your ass, the best bet is to talk to them one by one. You only have one family and it will be this way for the rest of your life. Insist on the love aspect and ask them who is truely hurt etc pp. This forum is full with the arguments. In case they are deeply catholic or so, you are screwed. See first paragraph again, prepare prepare prepare to not get caught. Or be ready to move out at your age.
In case other people caught you, deny deny deny deny deny deny, no matter how unlikely it is. Best thing is when they don't even know who you are. ASAP remove yourself, don't start a brawl.
As someone else said, in case the police show up, you say "hello, sir", you state your name and address, BUT NOTHING ELSE! They offer you a coffee, you say "I would like to talk to a lawyer, Sir." They ask you about the weather, you say "I would like to talk to a lawyer, Sir." They say "ok, this is a bit annoying, can we talk off the record for a second?" you say "I would like to talk to a lawyer, Sir." Follow their directions where to stand, sit and whatever until you are free to go, but say nothing resp. nothing else. Not on the drive to the station, not on the drive home (in case they are so nice, but you should soooo deny such an offer and walk instead), not to a plain-clothes officer, not in the police station bathroom, never never never anything else. Don't use your cell phone to call a lawyer from the station, and not within the same cell-phone tower zone as the station, don't use their landline. Get where this is going?
Assume everyone who could get you busted, because they pieced together your zooness and name and address, will either fuck with you or throw you under the bus the first chance they get.
As you see, most of this is about don't get the fuck caught in the first place.