Is it possible that I'm not eating enough and that's why I'm getting sick?

Well, I'm not a doctor. But that doesn't sound like nearly enough calories for your body to function properly.

Does all food make you nauseous? Even, for example, what your roommate makes for dinner?

My best advice would be to make an appointment with your primary care doctor, and tell him/her this - all of it, even the parts that might be embarrassing for whatever reason. If there's an underlying health issue at the root, he/she will be able to figure that out; otherwise, they can refer you to a dietitian / nutritionist who can help you get things back on track.

Make a conscious effort to eat sufficent meals for one day at least ( today/tomoro ) even if you don't feel hungry force yourself to eat breakfast lunch and dinner, look at it as eating for function over enjoying the meal, maybe you'll feel back to normal after getting some nutrition back into your system, one meal a day is nowhere near enough for anyone

Try protein/ supplement shakes or drinks to start with, if you can keep them down then hopefully you’ll start feeling a bit less sick and will be able to increase your food intake.

It might be a blood sugar issue like diabetes or there’s a chance you could have liver disease so still check with your doctor I’f it doesn’t get better.

Totally possible, a friend of mine had the same problem a couple of weeks back, she also used to eat very little and fainted one day. Turned out she had extremely low blood pressure, I recommend you should go to doctor.

Definitely. You need enough calories and sugar to keep yourself going, skipping mealsis a bu mistake. If you're feeling sick when you eat you might have an ED, so please get checked out.

How long this been happening? Was a week for me at the beginning of this year, 100% same thing u are going through.

make sure you're getting your electrolytes too. I get weak, dizzy, and nauseous when I'm not getting enough salt.

The coffee might be reducing you appetite. Yeah you need a checkup to see why you fainted.

Yes. It is exactly why you feel so crappy.

You need to eat more than one meal a day. Water is good but it is not going to give your body nutrients.

Coffee does not help if you aren't eating

Almost sounds like morning sickness

Sounds like your not eating enough

Speak to your Dr ASAP