It's helpful to know the limits of the ways in which your body can harm you.
You may fall asleep, but it doesn't matter. It doesn't matter if you have already slept most of the day. You will wake up again in time. And it doesn't matter if you wake up in the middle of the night or the middle of the day.
You may pass out, but you don't have too far to fall. The worst you can do is bruise. Once you're down, your blood pressure will right itself and you'll come round before too long.
You may throw up, but perhaps you need to. Perhaps you'll feel better.
You may be confused, but you are not going to make a fatal error. Nothing of great importance is depending on your clarity.
The pain is intense, but nothing is going to break or fall off or explode. And it will stay on the inside; no poisonous creature is going to burrow up through your skin and gnash its teeth at you.
You are not going to stop breathing. You will probably keep breathing for decades yet.
And pretty soon, you'll feel much, much better.