I am actually going through the same thing right now. We had a baby after several failed attempts and 9 months of problems. She's 6 months old right now, and I am just feeling normal again. My husband gained all the weight during the pregnancy - he's so overweight that the doctor is threatening him about it!
Our sex life is almost non existant. My desire is completely gone. I found that I didnt want sex no matter the circumstances with DH, and it became a huge problem in our marriage. We tried everything under the sun, and still not much more than a flicker in the flame.
I was with the kids all day, working part time at night, and when I got home, he wanted to jump my bones. Well, needless to say, the last thing I wanted was his big butt on me after all those hours of constant need from everyone else.
We even tried leaving the girls with family for an adults only camping trip with friends, and we talked the whole way there. After what I considered "whining" from him for over 2 hours - it was really him just explaining his feelings, but I was very defensive about it - I finally broke down and admitted the the attraction had changed when he changed and I wanted to work together to fix it.
Like you, we joined gyms and even got hundreds of dollars of equipment for our basement. They are now collecting laundry and dust.
In addition, I found out, at a recent OB aoppointment that my birth control was effecting my sex drive as well. I was on the Nuva Ring and it has estrogrene blockers. Once I got off that (on an IUD now) I have noticed a huge difference in drive.
I still have issues with DH's weight and interest, but we are working through it with books, movies, and date nights. I also find that me working out during the day when the baby is napping, or taking her for walks makes me feel better. In turn, DH sees it and makes attempts. Its helping, but we arent there yet.
So, I guess, after my long response, my short response would be: you arent alone. Dont feel shallow. talk to him about what you want or need. Dont allow him to force you or guilt you. take your time and let him know in any other way possible that you love him.