I feel lonely and afraid all the time...?

I have a great husband who works hard to give me everything I could want and need in my life. He is there for me emotionally when he can not be here with me physically. I just feel alone all day long and am starting to be afraid to do normal things like leave the house, drive my car, get a job or even get a pet to be wih me. I am afraid all the time and can not stand to be away from him. We love each other and have been together for the last eleven years, but this is starting to scare me. Is this obsetion or some sort of mental illness? I guess I am just looking for a little advice or guidence as to weather I am going crazy or not. What can I do when I am alone all day and scared to death to do anything?