Am I a nympho? Why doesn't my boyfriend want to have as much anymore?

My boyfriend of a year and I used to have pretty much everyday (or at least every day we got to spend with one another) and then 2-3 times a day on the weekends. Once before going to sleep, once after waking up and once or twice in between! I lost my virginity to him and he is my first love. Consequently, I can't keep my hands off him! But lately, he only wants to do it like once on the weekend and I only get to see him once or twice a week so... He says hes tired and one time even initiated with "Ok I'm tired" and proceeded to roll on top of me before sleep. Aka lets get this over with?!? I don't think hes cheating on me and I know hes in love with me, but I'm not his first. He has had MANY women before me (Upwards of 40...ew don't worry I got him tested). Do you think I'm a nympho? Or maybe the novelty of has worn off for him?