He just doesn't want sex!!!

So I have been married for six months now and have been with my husband for 6 years. In the beginning of our relationship he wanted sex ALL THE TIME! Now, he just doesn't. He plays video games from the time he gets home (2pm) until bed (12a) and once in bed he's too tired to do anything, but I work a higher paying and more stressful job than him working 50 hour weeks to his twenty but I still want sex. He recently told me that because I sleep naked, he sees my body so much it's no longer a sexual image for him. He also called me a "floppy mattress" and said I don't move and sex is too much work. I have been with many men before him with no complaints! I've even been told that I e been the best one guy has ever had! My husband was a virgin before me and I've been his only. I've taught him everything he knows and it's so frustrating that now, I get nothing! It's gotten so bad that sometimes the thought to just leave him comes to mind or even to cheat, but I could never hurt him that way. I want a baby so bad too but that doesn't even look like it's going to happen. Any ideas what I should do?