Crystal Meth Nightmare, anyone been through it?

My older sister sold the stuff hence I got my first taste at the age of seventeen, it was supposed to be a one time thing but I soon found that I couldn't stop, more-so that it was free. I could sing like I never could, play basketball even if I never practiced before, but then I lost too many pounds, had a stomach ulcer because I never ate, and I was so paranoid that I very rarely went out of the house. It took me a year before I could find it in myself to stop, all I had to do was contemplate on the many opportunities wasted because I was high. Sadly my sister still continues to use it. I haven't seen her in a year.