I went through a similar situation. You go through different stages in life. There are periods where you go through physical changes and mental phases. For either reason men and women can lose their libido. The desire , the passion , the physical ability to want and have sex is just not there.
You have a lot to unpack in your post. The bottom line , IMHO ,
is both of you are going through severe physical and mental changes. I think both of you would benefit from individual and then couples counseling with someone who can help you better understand what's happening in your head and body.