Definitely see a doctor. And thin people can have sleep apnea.
I have scheduled an appointment at student health; apparently they're very busy right now, so I can't get in with a non-urgent matter for a couple of weeks.
Are you a young person? If so, this might improve over time.
Hm. I am in my late 20s, so I doubt this has much to do with it (although, I guess it was worse when I was younger, but it hasn't improved enough with age that I would imagine this is it).
Hopefully, the doctor will be able to prescribe me some sort of supplement or medication to help with it. I'll keep y'all posted.