Hi, For The Past Week I've Been Having Random Episodes

Hi, for the past week I've been having random episodes of weakness and nausea. I will usually get these symptoms when I wake up and not eat breakfast for a bit; if I drink too much water after eating (or if i have too much water on an empty stomach); and during long periods of not eating.
It starts with a pain in my stomach, then almost immediately after that I feel light headed and nauseous. This won't go away until I snack on something. If I drink water when I feel like that it makes it worse and makes me feel weak and like passing out/vomiting.

I've been doing some reading (as an amateur) and I don't believe I have anemia or hypoglycemia. I am leaning towards me believing I have an ulcer because 2 weeks ago I took extra strength cold meds and would sometimes take 1 or 2 extra because I had a bad cold. Could that have anything to do with it or is it something completely different?