is this just a cold, or what?

for the past few days I've had a pretty bad headache and been tired. yesterday I was at my SO's house and toward the afternoon/evening it seemed to get worse, I felt all warm and tired (to the point where I felt too tired to even EAT) and queasy and achy but I took Tylenol. It allowed me to just get up out of bed and walk but once we got back to my house I felt really dizzy and sweaty and tired. This morning, however, it didn't feel as bad when I woke up BUT I was parched. My whole mouth was dry and I could barely make enough saliva to moisten it. I got up to pee and get some water, and I started to feel weak, a bit queasy again, and dizzy along with a minor headache. Is this just the start of a cold or what? It's weird esp since I don't feel as cruddy when I'm in bed.