Me in my head: frantically starts trying to think up plausible excuses to get out of going without hurting anyone's feelings, once again forgetting that they know about my social anxiety and would probably accept the true reason for me not wanting to go
Not here. Normal is at least 5 minutes early and the fashionably late types come on the dot. If you end up even 5 minutes late, you should inform the host immediately when you realize you could be running late.