Perhaps dehydration, or low blood pressure
Yes I was thinking low blood pressure or perhaps low blood sugar. It could also be an ear /balance problem. Try to eat regularly with some protein with each meal ( maybe smaller meals about 6 times a day with protein). Protein stabilizes the blood sugar if it is low. If it isn't a blood sugar problem you could try takikng benedryl at night and see if this dries up an inner ear problem. It could turn out to be neurological. So, the best thing is to see a doctor but if you can't afford the time off you can try these things one at a time and see if there is any improvement. if not then see a doctor.
mkh9
Good suggestions! In addition, you might start taking a high quality vitamin/mineral supplement (not the cheap box store brands). Many people are deficient in something, thanks to our modern diet, and deficiencies can cause all sorts of problems.
If these feelings don't go away soon, go see a doctor. It could be early symptoms of something bigger, such as fibromyalgia or Lyme.