Hello Erica and welcome to the site
Living with a person who as general anxiety disorder as you found out can be very overwhelming, altough you want to help your husband comes a point where you dont have the tools or the knowledge to do so and yes it drains your energy as your left in charge of everything...I can only speak of my experience with GAD and your question's did hit home, meaning I remember all to well being in the state that your husband is in.
I trough some therapy and medication have a good quality of life it was a long and bumpy haul, learning to live with GAD is not a overnight thing believe me but again it is possible.
If I may I would like to suggest that you start focusing on you as you said its very draining and in my view you need to take care of your basic needs.
Try to find a psychologist or and a support group in your community where you will be able to talk with people who are going trough the same issues as you remember that your not alone.
Keep us posted on how you are doing
I hope this was of some comfort
Suffolk/ for/ suffering folks