First off, lots of people do things that I choose not to. They smoke weed, the party hard, they have sex outside marraige....etc. Just because they are doing it doens't mean its right. They have to answer to God for what they do. SO don't be pulled in by peer pressure to sin. Because just as they will have to answer to God, you will to. And God isn't going to like it if you say "Well they sinned, why couldn't I!". You know the rules of the bibles.
Also take note that the bible never says when your a christian life will be perfect and happy. Its a hard life alot of times. We have to sacrifice alot and be ridiculed by others. Even Jesus when on earth was tempted by the things that go on down here. So if he was tempted...we will defintly be tempted!!!
Lasty and perhaps the most imporant....you should be using God as your role model/example. We are to be like him. Not be like a human who sins daily. A good saying I was told when it came to wanting to do what others did was "If your friends tell you to jump off a cliff...will you?". Ignore what others do/have.
Beacuse not only is it a sin to do the stuff that they are, but by being jealous/envyious of what they can do, you are sinning even more! Does that suck sometimes? Heck yeah, I can admit that! But what matters to me is what happens when I die. So I try to live like Jesus.
Also if you think about it...what does anything matter as humans? Having a fancy car, designer purses, big tvs....this is all temporary. When we die none of it goes with us! Our real treausers are on heaven! Now you might say "But I'd still like to enjoy my life here anyways!". Well you can, again thats your choice! But, isn't a lifetime of hardship worth the price of everlasting life? When you do die and the universe is destroyed, God will create a new earth! We get to live here (well there) with perfect bodies and never have to worry about sin! So I'd much rather suffer here and get rewarded later then enjoy here and suffer later....for eternity in hell.
Don't look to much into that. Many people say "Well...its ok if I sin because I can just ask for forgivness!". This is not true. If you are purposley sinning then using forgiveness as a way out each time so you can just sin again, then God will not accept that. He knows your motives and your thoughts in everything you do. Remember that! Because on judgment day he will replay EVERY good and bad thing we did in life and at that time no excuse will matter.
Now, this doesn't mean you won't sin. We often will sin over and over and over on the same thing. This is why we have to get better and try not to sin at all. We are sinners at nature. Just keep on working on your life and making it God oriented. Fight through this battle and the victory after death wil outweigh ANYTHING you "could have had" in this life.
I'll be praying for strength for you!