Hi, and thanks for your medical question on eHealth forum
What you have (floor under me is moving) while standing up, is probably postural hypotension or sudden fall in blood pressure on changing position from lying down to sitting or from sitting to standing.
Dehydration, certain medications, heart problems, untreated diabetes, and nervous system disorders can all cause this. Certain internal ear problems can also affect blood pressure monitoring by the body by not properly signaling a change in position. Compression of cervical spinal nerves too can cause some amount of dizziness. Diabetes, hypothyroidism and hormone imbalances too can cause this.
Blood pressure monitoring, blood tests, tilt table test, EKG, heart echo, ambulatory blood pressure recording are all required.
However a confirmed diagnosis cannot be made on net. Please consult your PCP to rule out the possibilities one by one. Please consult your gynecologist too. Hope this helps. Take care!