sounds to me like you have one of two possible problems. Either:
1) You are a bone idle lazy fecker and need to pull your finger out before your wife leaves you or
2) Your wife expects you to do more around the house than she does.
I would lean towards 1. Sounds like you need to do more around the house and show a desire to spend time with her, is it really that much of a drag to spend the evening with her rather than go to the gym? If it is then you have a very unhealthy relationship and need to get counselling. I would say she is probably feeling resentful that the house is a shithole and that you aren't prepared to do anything about it and would also prefer to spend time at the gym rather than with her.
I've been married 5 months now although we have lived together for 2 years and occasionally get the same thing, mainly due to me not pulling my weight in the household chores. I work long hours too and commute 80 miles each way to work each day so leave the house at 7:30 and get back the same sort of time in the evening, that doesn't mean that my wife gets the honour of being my house maid (well not always) as she works full time too.
Firstly you should be sat down and talking to her about it, rather than talking to people here. And don't be all defensive when you do sit down with her to talk about it - acknowledge your own mistakes rather than looking to blame her for everything.
Hey, at least she still wants to have sex with you, things could be worse.