Terrible lightheadedness....well beyond what is considered 'normal'

Has anyone experienced this?  I am almost 7 weeks with baby #2 and, for about a week now, have been extremely lightheaded and dizzy pretty much constantly.  With baby #1, this went on from about 10 weeks to about 23 weeks and they never figured out what caused it.  I've read all the causes and have tried many remedies, but this seems to be much worse than 'normal' pregnancy symptoms - I had to quit my job last time 😳 Already having one beautiful baby to take care of, makes the sickness harder to handle this time around.  The easiest (and worst) way to describe it, is that I feel like I drank way too much.  (Which I, of course, have not!). Anyone have anything similar??