Dear Kissa, life has so many surprises and great moments...and great people.
We just need to look for these things and people a bit more.
Keep you strength and values close to you and to your heart, they are very important to you and to your happiness.
Sometimes, we just grow up quicker than the friends we have. Then, it's time to move on, and find new friends to hang out with. Friends who think like you...have the same values, and understand you better.
Sometimes we see ourselves caught in between a small circle, and forget to look outside of that circle. There are much more people for you to meet, than these four friends you mentioned.
And when they grow up too, they will become your close friends again.
Meanwhile, go out and meet new people, friends who will make you laugh, and keep you company at times which you need it most.
Drugs, and all that follows it, are not good, and is an escape. Life is not meant to escape from, it is meant to live through. And to live through life, one needs to look for the true happiness, true friends, respect, and most of all, keep within their hearts their values - because that's the place where no one can destroy it...in your heart.
I hope you find new friends, and live life to it's real meanings.