Called Fat...Embarrassing story (Humiliation)

On friday, I was having such a good day that day, and I was actually smiling. Something I hadn't done in a while. And I got into my weight training class and we were on the last exercise of the day which was planking and I was doing it with some people who I met on my first day of school.

So I wasn't doing my planking correctly, and I fell down within the first few seconds, and instead of helping me with planking, my WT coach pokes fun at me by saying this

Coach: "Two Seconds!! what a whole new record, for a fatty."

Fake Friend 1: "well it is true, she can't do jack shit if she even tried for a doughnut."

Then every one in the WTR literally stops what they're doing and looks at me, like I'm some kind of freak. And I leave for the locker room 20 minutes before actually being dismissed. And when its actually time to leave neither of them apologize, and all weekend I've been thinking about skipping school, and faking a stomach bug.

I don't want to go back there if I am going to get picked on whats the actual point in going there. I feel like I can't work out without judgment...