i'm pregnant with my second as well and i've been feeling the same as you! i'm 37 and 4 right now, but i've been feeling like a pile of dirt lately. i don't know if it's labor coming, because i feel like somehow i've forgotten what that's like -_- but i'm ready for it to be over.
My first is only 18 months so I thought I'd remember better but I agree with you, I feel like I've forgotten everything. I just got checked at my appointment yesterday and while I am dilated 3cm (which I was around this point with my first too) my dr was honest in saying I could feel like this for the next two weeks :(