It is your day, don't worry about pleasing others by attending. This is all about you, especially at this point. Get out of town, look up a long lost friend. See a movie. Buy a pet. If you worry about being alone on this birthday, consider the fact if you slip up and fall back in, you may be alone for the rest of your birthday's..in a box in the ground. I am celebrating my 40th birthday sober in two weeks. I am already living it in my head, without the booze. You can too, you just have to picture it. You can do this. 30 years old is a brilliant time to regain you life. Wish I did back then. Don't miss another day.