In over my head.
Many of us have been there! The first time you hear a diagnosis like that, it's scary. Just take a deep breath first. Remember this is the same kid you had before the diagnosis, no matter how scary it sounds. Now, you have the information to help you deal and get the services you need. That's actually a great thing! Is your son in school and who did the diagnosing? Both those places should be able to direct you to services in your area.
Take a few breaths (and I don't mean that in a patronizing way). Like the pp said, nothing has changed with your son. He has had Asperger's since he was born, but it's just now being called that. It sounds like, regardless of his diagnosis, some of his issues are causing problems in your family. I think it's always a good start to find a competent child/family therapist who specializes in Asperger's. Is it possible that your husband doesn't fully understand where your son is coming from? A qualified therapist can hopefully offer you all some advice regarding how your family can best move forward as a group. Also, maybe there is a local support group you can attend? Quite honestly, I didn't find my local support group that helpful, but a big part of that was due to just being out of alignment with other folks' parenting philosophies - i.e., they were uber mainstream and behaviorist, which isn't what works for me.
Can you tell us a bit more about your son's or your family's specific struggles? Are you looking for books, blogs, therapy suggestions, etc.?
And please know that this board is here for you. The diagnosis can feel a bit like a slap in the face (or punch to the gut) to some folks, and it's hard not to feel the need to get out and "do something for my child." It's really cliche, but I would offer the thought that this really is a marathon and not a race - as is all of life. Good for you for reaching out :).
I'm a reader -- when things go wrong I seek out books. "Quirky Kids" is one of my favorites:
My Dh and I have had some tough times in our relationship because of seeing things differently regarding our dd (who is 15 and also diagnosed wtih Asperger's). I tend to be a meet-it-head-on person, and he likes to live in denial. I just go ahead and do what I think ought to be done. The last couple of years, I've been able to see really wonderful things about his denial. He has a much greater capacity than I do to continue to see our DD as perfect exactly the way she is and to just enjoy her. I'm always worried and trying to fix things. She needs a parent who tries to fix things and seeks out therapies and the right schools and all that, but she also needs a parent who sees her as pretty much perfect. She's needed us both. (2 parents in denial would have been a bad thing for her, and I think 2 parents like me might have made her a little crazy )
As far as how to feel, you feel how you feel and it might change in a moment or a day and that's OK. There's no particular way that you are supposed to feel.
As far as how to act with him, there's no need to act any differently. He's sill the same kid he was before the label. If you are having specific issues and problems, then the label can sometimes help point you toward ideas to try -- things that have worked for other kids with aspergers. It might help you understand him better, or help you explain him better to others (such as his teachers).
Oh good! It feels so much better when you get those supports in place. My ds is on the spectrum and I felt that floundering feeling until we got things in place for both him and us. Good luck on your journey.