In HS, I was a smart kid and a decent runner (16:25 XC). For college, I went to a conservative D3 school about 2 hours from home. Semester 1 of college, I partied hard, quit the XC team and eventually dropped out. I then moved into a nearby trailer with one of my buddies who actually had his s*it together. While he worked hard, attended school, paid my bills, and provided me with food, I did drugs and had a string of unhealthy relationships. I worked the midnight shift at the local Burger King, but got fired from that for getting drunk and skipping work a couple of times. Then, I got an MIP and instead of agreeing to drug tests every month, I CHOSE to sit in jail for 25 days so that I could avoid probation.
Eventually, my buddy put his foot down and said that he was not putting up with my crap anymore and he begged me to understand that I needed help. I moved back home, started waiting tables and making $20/hr. I decided that I did not need college. For the next 2 years, I snorted coke on weekends, smoked weed nonstop, and went to the bar every night of the week. Lots of good looking girls sprinkled in too, but it wasn't really all that glamorous. I was "happy", but also extremely unhealthy and never even thought about running.
Then, I met my future wife. She thought I was fun at first, but eventually realized what a joke I was. After about 9 months, I asked her why I hadn't met her parents yet (they lived reasonably close) and she said, "Because you're a total f*cking loser. I love you, but you aren't exactly a prize. Maybe if you could get it together."
Shortly after that, I got fired from waiting tables for being drunk on the job. That was my "rock bottom". I signed up for community college classes the very next day. I started running shortly thereafter (~2 miles in 16 minutes if I recall correctly, I puked afterwards). After a few months, I had received my first ever college credits (at the age of 21), and I finished my first 5k since HS. I ran it in 18:24.
Fast forward 8 years and I am now happily married, have a job that I LOVE (math teacher and track/XC coach), and rarely even think about drugs and cigarettes. I run every single day and have gotten way better than I ever was in HS. Life is truly fantastic and has been for the last 5+ years. If it can happen for me, it really can happen for anyone.
Good luck, OP.