XR metformin

Anybody take XR Metformin?

I've been taking regular Metformin for about 3 wks. I started taking 2 a day for about 3 days and I messaged my OB asking if I could take 2 at night because I get sick during the day. I should've just pushed through it but, she prescribed XR metformin and it says only 1 a day at it 750mg..so do I work my way up like the regular metformin or just take 1 XR? I'll call her and send her a message but, I'm just confused