So I remember being 16, and wanting to explore everything. It's totally normal.
Can your boyfriend come to see you? Can your parents get to know him? Start trusting him? Lay off the hickeys for awhile - and really, there's no need for them, as all it does is announce to people that you were hooking up in some way.
My parents would have NEVER let me sleep over at a boy's house at 16, and I can't imagine letting a 16 year old do it now, even though I'm older and cooler. ;) I'm an adult, and since I'm not married, my mom probably wouldn't let me share a bedroom with a man I'm not married to, even now. It's just the way she feels. I respect her rules at her house.
Do you know what your boyfriend does during the times you aren't together? I ask, because yes, there are consequences to having sex, at any age. Have you talked about sexually transmitted infections? Pregnancy prevention? Has he had sex before? Has he been tested before? Is he as serious about this as you are?
You may well end up married to this guy, or you may not. Statistically, you won't, but you never know. Right now, you need to work with your parents to earn their trust back. You are always your first priority - not a boy. Make sure you have your best interests first, and right now, that's not fighting your parents. Yes, they may be strict. My parents were really strict, and I got through it. You will too, and their strictness may protect you from some mistakes.
So for now, work with your parents. Earn their trust. If you want to be treated like an adult, act like one. Be responsible, honest, reliable. If you say you'll do something, do it. If you say you'll be home at a certain time, be home at that time. If there is a party and everyone is drinking, leave and tell them that's why you left. Show your parents that you can be trusted, and that you have good judgement.
It will take time, and it may be like this until you graduate and go to college or leave after high school. That's okay. If your boyfriend is the one you are meant to be with, he will still be there at that time.
Oh and if he is pressuring you at all, he's not the one for you.