Low blood pressure ?? 35 Weeks

Sorry for the long post, but I felt like some explaining is needed.

I'll be 35 weeks tomorrow, and had a doc appt on Friday, while I was there I got very hot, dizzy, thought I was gonna pass out, felt very almost "unconscious" or "unaware".. I couldn't sit in the chair anymore I thought I was gonna fall over.. She had already checked my blood pressure once and it was fine, so she moved me to a room and laid me down, checked it again and it had dropped significantly.. She went and got my doctor and told her what happened, she then told me that it was because my baby is pressing on the nerves in my spine, and valves that run to my heart, causing my heart to not be able to pump blood properly.. this has been happening off and on since maybe 24 weeks I think, and she has always just told me it's part of being pregnant and nothing to worry about.. it's now Sunday and I'm worried about it now because I literally can't do anything except lay down without it happening, and sometimes it just happens when I'm laying here..

If anyone has ever experienced this or knows anything that can help with this, it would be greatly appreciated!

I'm due the May 28th, but she told me on Friday that I probably am not gonna make it with her after the second week of May, which is still 3 weeks away and I'm not sure how to deal with 3 more weeks of this..