I'm so sorry you're hurting so much, ruby2011!
Have you already tried therapy? I feel like that may be REALLY helpful to help you to deal with your insecurities especially since they date back from so long! I also completely agree with divine1966's wise and wonderful advice about waiting before saying anything and to make sure that you're not acting in a way that may be uncomfortable for others! Other than that, perhaps you could just try to be honest with you Supervisor and coworkers and tell them what the reason you're behaving this way is! Hopefully they'll understand what you mean and perhaps they'll even try to HELP YOU OUT! If you feel like they will understand, I'd say it's worth trying!
Of course ALWAYS remember that we'll be here for you and WE'LL NEVER JUDGE YOU! THAT'S A PROMISE!
Please keep us updated on your situation if you can and want to, ok?
WE DO CARE ABOUT YOU! THAT'S A PROMISE! I hope things will get better soon for you! WISH YOU THE BEST OF LUCK AT WORK AND IN YOUR LIFE! Sending many AWESOME, kind, safe, sweet, warm, wise and WONDERFUL HUGS TO YOU, RUBY2011, JUST LIKE THE WAY YOU ARE!