Hi Spacegirl, oh boy you are in a pickle!
All you need to know at the moment is that your husband's religion is crazy. Keep the discussion really simple, which will be hard because he will try and drag it all over the place. Your points could be something like:
You do not have the same religious beliefs.
A house is a shared space where both partners should feel equally at home.
you're not prepared to compromise on the Christmas tree and he needs to accept that if you are to feel that where you live is your home.
You have given up birthdays, Easter, having children(!!) for him. Is he prepared to give this up for you?
Stick to your few points, don't get distracted by arguments about pagan origins, don't get sidetracked down waffle alley and don't give in!
Once you get through this I'm afraid it's not going to get easier. The organisation will always be interfering. There will always be some issue unless you roll over and become a JW (and give up your free will and thinking ability). DON'T DO THAT!!!