Help me out

So I have social anxiety/general anxiety. I’m a college student and this week has been my first week. On Tuesday I had a class where I didn’t know anyone and I literally started having the worst anxiety attack I’ve ever had in class. I felt like I couldn’t breathe. I felt like I was literally going to pass out. I felt like that up until I got out the door. Literally the second I got out the door I was completely fine. I have that class again in like 12 hours and I wanted help to know what I could do to calm myself down. I feel like I tried everything. I tried deep breaths but each time I would take a deep breath I actually felt like I was gonna faint. I tried to write to distract myself. I tried what felt like everything. Help me though please