I’m very sorry it took a hospitalization to give you a wake-up call. But the important thing is that you did wake up to the fact that you were on a course of self-destruction and you’ve done something about it. Good for you for quitting the drinking. That’s not easy.
What your friends may not know is that you are as embarrassed as they are about your past behavior. You got a note. You didn’t have a conversation. If these were good friends, I think it would be worth an attempt at contact to tell them that you’re sorry that you lost control and that you’ve quit drinking. Ask for their forgiveness and see if you can move on.
It these people were drinking buddies and not particularly good friends, maybe it’s best to let them go. You need real friends in your life who you can hang out with and talk to. Get involved with places where people do the kinds of things you love to do and friendships are likely to evolve. Congratulate yourself on making a life change and set your focus forward to a healthy future instead of back to past mistakes. You’re only 24. You have a lot of life ahead where you can apply a lesson learned.
I wish you well.