It is good that you are seeking help for your anxiety but in the meantime, you need to find a way to deal with. The trick is to take things in small steps and build up your confidence. Taking everything into consideration all at once just overwhelms you and makes you feel a lot worse! Break things into chunks and don't put too much pressure on yourself - some things will work, some things won't - but by trying you are opening up the possibility to deal with these life situations more.
Take your meeting with your friends - they have agreed to meet up which still shows that they are open to your friendship. Don't place too much expectations upon yourself - just go to meet them and see what has gone on in your friends' lives since you last met.