Hi, lola.
I think it's pretty common in early sobriety to feel that one is "boring" or "no fun."
You are still getting used to life without alcohol, and it's a process.
Fact is, you are far more interesting now that you are not slurring your words, picking fights, getting maudlin, or one of the many, many unattractive and damaging behaviors associated with overdrinking.
It is often recommended that we avoid triggering situations early on, like weddings, parties, hotel events, etc.
If you absolutely must go ahead with the birthday event, plan in your head how it's going to go, and where you might slip up.
Drink ginger ale or tomato juice. Have it in a wine glass if you feel self conscious.
I promise you that as you get more sober time, these events will become less fraught.
Good luck.