very dizzy, can't breathe?

I've passed out from not eating enough during the day, but I've had 3 meals today, all with plenty of protein. I've been drinking plenty of water but I'm very dehydrated and I can't catch my breath or even walk up the stairs to tell my mom i need help? I'm 26 weeks and 1 day any haven't had any problems with this since I was 7 weeks but I was having a lot of problems with my blood pressure. Could it be that again? What can I do? Because I know that not being able to catch my breath just sitting on my sofa isn't healthy. Do I need to go to the emergency room and check on the baby?? (No spotting, severe cramps though)