Welcome, Luis. I'm so glad you've decided to reach out for help. At your age people tend to keep going with their addiction for many more years, so be proud of yourself for knowing what needs to be done. It's obvious you are intelligent and capable of having a great life - it all lies ahead of you.
Reading other people's stories on SR made me want to rise above the hell I had made for myself. I wanted what they had acheived. Everyone understood and had been where I'd been - I didn't have anyone in my life that really got it, until I came here.
I hope you'll check out the Drug Addiction forums here. Have you tried NA? Right now you're in a vicious cycle - there is a way out and I believe you're ready to remove the poison from your life and begin to work on why you feel the need to get numb. Please let us know how you're doing. We care about you.