It actually is quite common & for most it’s temporary.
I’ve never had an issue with my blood pressure, 120/80, regardless what I weighed. Though I did always have a tendency towards a low BP - a family thing - where it would drop & I’d get light headed, loss of vision at odd times. Now my BP is low all the time & I experience orthostatic hypotension (postural pressure drops) daily. (And a lower heart rate too.) The vision loss, slight throb in my head, is just part of my life when getting up (from sitting, lying & crouching/kneeling), doing too much, etc. I think carrying weight kept my BP at a healthy level & the low BP is actually normal for me. My GP isn’t too concerned. I guess because I manage it.
Keep your fluids up, add a little salt too your diet. Take your time getting up giving your heart a chance to get the blood back up to your head.