Whats wrong with me???

I'm 15 weeks pregnant, and for the last week and a half, I have had really bad headaches off and on all day. At first I just figured I needed to drink more water. Well that doesnt help at all. Also I have been getting light headed and dizzy when I stand up, and black out (not pass out, but everything goes black) and my heart beat has been acting weird. It beats really hard, and faster than usual mostly if I am picking up the house, but sometimes when I am just sitting. I get out of breath faster than usual, and have to sit down... I didnt experience any of this with my first pregnancy other than the occasional headache, and when I was 36 week or more getting short of breath. It seems to be getting worse everyday. Any ideas on what this could be, or advice?? I have a 15 month old, so just resting isnt really an option lol.

I'd be going to see a doctor. It sounds like it could be blood pressure related maybe?

Its very common to have all those symptoms when your pregnant i have been getting a lot of headaches also take it easy and try not to move to fast  

You have to move a lot slower. I've noticed this as well. Drink a little caffeine. I had a headache for months I til the dr told Me to and now I rarely get them anymore. My bp keeps going from high to low. It's random. But just slow down and rest when u need to rest.