To quit or not to quit

Hi!

I’m a student whose working full time in the summer at Tim Hortons. My question is basically the title, should I quit?

I’ve worked there for just about a year and a half, and I hate my job. Some shifts are okay, and others are terrible. On top of that, my manager is genuinely awful. She can be really rude and likes to punish her employees (me, a lot) if they book off time or call out. She doesn’t give shifts consistently, so some weeks i’ll work 35 hours, and others i’ll only work 3.
The reason i’m debating not leaving is because I really love my co workers. The work itself gives me a lot of anxiety, but if i’m working with people I like, my shift ends up being a lot of fun.

Moving onto the next part, my old district manager messaged me a couple days ago and offered me a position at her new place of work. This is an independent grocery store where she manages the food preparation aspect of it. The job seems a lot chiller and a lot less stressful.
One of the reasons i’m doubting switching jobs is because i’m terribly anxious, and although I hate my current job, i’m comfortable (and good) at it. Starting a new job, learning everything all over again and having to go through an interview is terrifying.

So, what would you do, and what’s your advice for me?