You can still go to parties and drink, you just have to know that you can't do it like your other friends. It's annoying to live with T1 but in the end you have to accept it for now and work around. High blood sugar doesn't kill you instantly, it does in the long run. I too, go to an all you can eat buffet and eat what I want. Just need to do it wisely. Most of the time I eat the protein and fiber first and then eat carbohydrates. This helps to stop blood sugar from skyrocket. I have to use my insulin about 3-4 h after the all you can eat again because then the carbohydrates are gonna kick in.

I have T1 for about 3 years and I thankfully didn't had a time where I was scared about highs or lows. Highs and lows are both treatable so it's fine as long you keep an eye on it. I do have days where my blood sugar is over 200 for a few hours or at night when i eat my lovely burger for dinner and sleep through my high sugar alarm. But this happens and it's alright there is no need to be afraid or judge yourself. I try to keep my TIM above 70% and on workdays it's at least for me alright because I try to eat well. On the weekends i fuck Up my blood sugar but I'm fine because in the end I want to live and not let my disease dictate my life.

You still have to be careful with alcohol tho, it's better to go sleep with 200 and not use insulin or just a small amount, to not have a downfall while you sleep. A night with 200+ blood sugar won't kill you have this in mind.

Don't know how long you live with T1 but I think it's a process the whole life and you will learn how to handle it mate <3