Changing schools for 6th form

I’ve been certain since year 7 that I was going to get out of my secondary school as quickly as possible. However, now that i’m mere months away from leaving, i’m TERRIFIED.
Basically, I need advice on where to go.
I really want to go to this different school that i’ve been accepted into; it gets amazing results, sends its students to great unis, and overall i’d have way more opportunities there.
However, there’s a part of me that’s terrified i’m not going to be able to make any friends there. I’m really shy, but I don’t really thrive on my own. I’ve had the same friends since year 5, and i’ve only really made a couple more friends in the past year. So, by staying at my current school, I’d already have friends there. But other than that, my current school doesn’t really have any other attributes, except for the fact that My current maths teacher is really good.
Advice? where should i go? And, to anyone who has changed schools for 6th form: how did you make friends?