If you google the words "emotional unavailability", you
will see a lot of explanations. I know it's not nice of me to mention these two words in your case because he is your hu*****and. I don't mean to be mean. What you are talking about (not only you, but also the other similar posts) just reminds me these two words.
There are various degrees of emotional unavailabilities. Some people have only a little tendency. Understand these two words may not hurt, although I understand that you love each other dearly.
