Op,
I feel for you. My (adult) DD has something similar, triggered a couple of years ago by who knows what... 
If I can précis things..
Your sex life was good (or at least, there was quite a bit of PIV) until you fell pregnant. (DP has never really done anything foreplay-wise.)
You had sex in more than one position prior to falling pregnant, but about a year before you fell pregnant, DP would only have sex with you whilst spooning.
During pregnancy DP didn't want to have sex.
After birth, sex was painful / difficult for about a year. Your health started to decline. Nobody knew why.
Due to your illness, you lost weight. Your DP was "aggressive" in his comments about your weight.
DP has changed his work, and now WFH, so that he can do the school run etc.
At some point your illness was diagnosed, you (hopefully) received treatment, and have started to be able to cope / live with it.
I realise that's cutting a lot of stuff out, (sorry) but hopefully, I have the bones of the issues..
Devils advocate mode
It kinda looks like your DP was trying to be a caring sharing husband.
How long where you TTC? Is it possible that he read somewhere that the spooning position was best for conception? That might explain the switch prior to you falling pregnant.
Why has he continued with this position - could he want another child?
Then he had 9 months of no sex, as he only did / does PIV, and didn't like the thought of having sex with you whilst you where pregnant.
Then there was a year where he couldn't have PIV. During this period, your illness took hold, and (maybe) you started to lose weight. DP thought maybe you had an eating disorder.
The kindest part of me says (and I can sort of see how he might have thought this way) that he is / was trying to do what he thinks / thought is / was right for you.
Unfortunately, he has never actually discussed any of it with you. Instead he has been a "man" about it, and believes he has taken responsibility for things that are going on in your lives.
devils advocate mode off!
I'm probably way off base with the above, but I wanted to offer a different perspective.
I do think counselling would be a good idea, unless you have made your mind up about your relationship.