welcome. I am also young and new to this, 24 years and woke up last monday with the same realization. I couldn't do it anymore, and after years of abuse and hitting the same desperation again and again, I decided to stop. I found this site two days later. I am eight days sober, don't feel great but compared to the first few days of being dry I feel amazing. Don't give up if you feel anxious, irritable, physical symptoms or cravings.. These are temporary and the alcohol detoxing from your body.
I hope you stick to this, I've had plenty of "drinker's remorse" hangover days that I thought the same thing, hundreds in fact, but the next day I had already forgot the misery and convictions I had the previous day and was already back out. Make it through that next day, get ahold of support groups and take it one day at a time. I'm only 8 days and my energy is already coming back, motivation and I wake up ready to face the day. It's not easy but it's not that hard either.. The benefits of being sober far outweigh the benefits of drinking, and your friends and family will respect you more for it.
Good luck, PM me if you want and keep updating on how you're doing