Vertigo? LBP?

Okay this is weird cuz it started a few weeks ago and it only happens when I lay on my belly and are on my phone in bed or on the couch at first everything gets blurry then my ears start sounding like there’s water in it swooshing around, (kinda like I’m holding a seashell up to my ear) and my stomach starts to hurt. When I close my eyes it gets worse it only goes away when I sit up and sway lol kinda weird. I had low blood pressure when I was pregnant and I think that’s what it is but my grandma says it’s how she feels when she gets vertigo. I’ve fainted multiple times before so I can kinda tell when it’s gonna happen and I thought at first that was it. Idk but it’s just new and weird. I never actually pass out probably because I don’t stand up just sit criss cross and rock