You're 32 with a toddler - I was much younger than that when I had my daughter and she still wore me out.
There are lots of things that can affect libido after a baby; some of them are physical, and some are emotional.
If he has "always complained" that you don't want sex as much as he thinks you ought to, then he knew what your sex drive was like before you got married. I'd point this out to him and ask why it's all of a sudden a deal-breaker.
Do you work outside the home and handle most of the housekeeping and child care at home? If so, then you're basically working three full-time jobs. In addition to constant low-level fatigue, there may be some unconscious resentment. I know that I don't want sex if I'm feeling unappreciated or taken for granted.
As for how much sex other women want, there's no such thing as "normal." Normal is simply a mathematical average. Some women have high sex drives, some not so much. It's not just a function of age either. I've known women in their 20's who have little interest in sex, as well as women in their 70's who were still sexually active. You can have your doctor draw some blood and check your hormone levels, and if they're all within normal range, then I'd say you're just one of those women whose sex drive is in the lower end of the spectrum.
Personally, I want it more often than my husband does. If he's too tired or just not in the mood, I have a vibrator.
Not getting as much sex as he wants is no excuse for him to be mean, and berating you and blaming you for his pissy mood isn't exactly going to make you suddenly want to jump his bones. If he's horny and you're not, he's got two functional hands.
Have you considered a marriage counselor? Perhaps a professional could help.