I've been with dh over 11 years, married for about 8, and I have to say that I experience the 7 year itch about once a year - I know his jokes, the way he eats bugs me, it fills me with horror to think that this is it for the next 50 years or so, and about every 6 months I'll get a major crush on someone (none acted on but lots of flirty emails).
We've a 2.4 year old and I'm 5 mths pg, my husband still fancies me but I can be pretty indifferent to him even tho he makes a huge effort to keep in shape and do romantic things.
What I've realised is that it is all cyclical, that it will pass and that it will come round again, but as time goes on I'm more prepared for it and know that it's just a phase.
The important thing is to try and talk about it with the partner, tho try and leave out any really irrational hurtful things you might be thinking, but try and come up with a strategy with him that will bring you together. We stopped eating in front of the tv and started setting the table and actually chatting, and we try and have a special date night every now and then so we get dressed up for each other.
I sometimes keep a journal and write all the stuff in my head down and try and work things out on paper, by the end of it I usually find myself realising that I have so much more to lose than I have to gain by jacking it all in. Then I make sure he'll never find it...
And as for the sex life, if it continued as it did in the early days we'd never get anything done. I find that too is cyclical, we'll go thro phases of great sex and phases of blah sex. C'est la vie.
Just remember, it won't get better if you keep in your head and do nothing about it, talk to someone, get it out of your system, try and change what can be changed, try and see what you used to see in him.
Do I sound like Dr Phil or what?