I'm really worried.

I'm five weeks pp, and after my delivery, (vaginal), I had a blood transfusion because I was lightheaded and almost passed out getting to the bathroom. Even hours after. I have anemia and had struggled with it more during my pregnancy, but for last couple days I've been having very bad headaches, almost passing out while sitting up, getting up, or even walking after a minute no matter how slow I do anything. Did anyone else have this problem? Should I get checked out?