Not sure what's going on... HELP!!

so I'll be 16 weeks tomorrow and all through out the pregnancy so far I've had a problem with getting dizzy spells hot flashes and almost passing out all at the same time meanwhile being soo shaky to the point I cant hold anything or even stand. I've talked to the doctors they took some blood but Said everything was fine. It's to the point I can't do anything anymore without this happening... I eat and drink as much as possible to try and not have this happen but nothing works. does anyone know what this might be? Could I possibly have gestational diabetes?