I don't quite understand. You turned on XMP on the motherboard? I don't think that's even possible.
Reseat your ram sticks, make sure they're in the correct slots as listed in the manual (usually slots 2 and 4), and see if that option becomes available.
If not, try one stick at a time and see if you can enable XMP.
Otherwise, reset all your bios settings to stock or clear CMOS, and try again.
I still find it really weird that you've enabled XMP before you got into bios, which is not technically possible.