What worked for me was facing my fears (Not the most original, but in the end is what works).
I felt anxious, embarrassed, out of place... i still do sometimes. When i wanted to go home because of discomfort (not just boredom), i stayed, no matter how bad i was feeling, until the event was at least almost over. And of course, i smiled, acted friendly and tried to have a good time.
Each week try to add a new "challenge", and keep the previous ones: walk straight, remain calmed (or pretend with your body language you are), try to strike small talk with people (nothing too long, just to overcome your fear), speak in a lower tone and louder (to avoid being unheard and unnoticed) (the lower thing is for looking more masculine)...
The thing is, to develop an emotional habit (calmness instead of axiety), you have first to train it mechanically.
The more you do it, the more you get used to, and the easier it gets.
(One more thing: you may be tempted to rely on alcohol or other drugs. Don't. It will harm you, and you will become addicted to how it makes you behave and feel. Drinking is not forbidden, but don't use it as an excuse to depend on it.)
And pray. You may not be strong enough to face this battle, but he will provide.
