To the OP:
I love walnut ice cream. If I had it every day, I'd soon stop thinking of it as something special and think of it as something mundane, routine. After a while, I'd probably lose interest in it. As long as I only have it occasionally, it retains its appeal.
Sex? Same-same.
I've been with my current girlfriend for about 10 months. Early on, we had sex two or three times every time she stayed overnight. Now we only do it once or twice. I expect that sooner or later, we'll probably only do it once per overnight visit. If we lived together, I imagine that 2~3 times a week would be just fine.
In other words, I think you're literally screwing her out of the enjoyment of sex. Give yourself and her a break, let the anticipation mount and then the appreciation will likewise increase.
Where have you gone, MikeBB? Are you still trying out your Xmas present? How is that nympho sheep working out for 'ya? I hope you're not allergic to wool.