Speaking as someone who started having sex at 14 because of my own wild hormones and pressure from guys, I would say you might want to consider pruning your list of friends, at least temporarily. Don't go to places like parties where you might be tempted to abandon your standards. Avoid alcohol and drugs if they are offered to you; alcohol is notorious for lowering your inhibitions.
I really feel for you. Have you talked to your parents about this? They will be on your side and will support you. They don't want their precious daughter to be hurt and will protect you in every way they can.
I also know what it's like to feel burnout with all those church activities, on top of schoolwork. When you say the pressure is coming from the church but not your parents, do you mean other elders? Members of a youth group? Family friends?
Think of it like this. You're becoming a young adult and are facing the pressures that young adults feel. Christians aren't immune from it, but Romans makes it clear that when we're in Christ, something has changed to make it possible for us to withstand temptation. Your carnal nature will be shouting and screaming for attention, and peer pressure will combine wth it, but God has said our old nature has been put to death. So you're hearing the moans of a 'zombie' trying to get your attention! Have a careful read through Romans which lays out the change that takes place in us when we're born again. Satan will try and tell you it's 'normal' to act on these desires, that everyone's doing it, but the truth is you have a Shepherd to guide you into right situations and protect and warn you away from bad ones. Your security lies in sticking close to Him because He has a better plan for your life.
I'm going to be praying for you - I never had the opportunity to hear the gospel or consider an alternative to hitting the sack when I was your age. You don't want to be dealing with pregnancy scares and the treat of disease (and the fact that if you do give in, the rumours will start to circulate, because people love to trash young girls' reputations and make them out to be sluts). Any encounters you have will affect your emotions and it's easy to find yourself in a kind of rut of behaviour. If you sleep with one guy and he leaves you quickly, it's so much easier to move onto the next, and it does affect your self-esteem.
I admire you for being concerned about all this; it shows that the Holy Spirit is alerting you to a potential threat and now's the opportunity to arm yourself in prayer and scripture reading.
If people start pressuring you about the perfect husband etc, remind them that God will bring that about in His own timing and you're going to rest in His will because that's the mature thing to do.
I'd be happy to talk to you about this privately if you wish; if so, please show this post to your parents and get their permission first, then send me a PM.
Love,
Jules