It can be hard to understand the challenges that your loved one with SAD faces. You might find yourself becoming impatient with his behavior when it interferes with daily living. For example, if your husband won't answer the phone, or your wife refuses to attend social functions with you, eventually over time you might grow resentful.
It is important to realize that while you should encourage your loved one to challenge her fears and experience new social and performance situations, you also can't expect too much right away. If exposure comes too fast, too soon, it will have the opposite of the intended effect and leave your loved one more afraid and anxious than before.
In the same way, be aware of your expectations regarding treatment for your loved one. Treatment for social anxiety takes hard work and he might feel mentally drained. It is also not a lifelong cure; your loved one may have relapses and needed additional help along the way. Having patience about the process will go a long way to lowering your expectations and making the situation better for everyone.