I know I should decide myself, but...?

Help! So I have to decide between sixth-forms for next year. It's between the school I'm at or another school. The school I am at is perfectly nice, the teachers are great, I will probably get my grades and I have friends there. However I am incredibly shy and recently have been feeling a bit inadequate there, I don't know if I'll break out of this if I stay, also the teachers don't really know me very well as I am so shy, so sometimes I feel left out when the other students are joking about. -The other sixth form has a great reputation,but the teachers are kind of snobby and I know no-one there. However if I go there I may be able to break out of my shell and feel happy and included, equally I may not make any friends and end up being friendless for two years! I don't know what to do! What would you suggest?