You might be better off in the Mental health area picklebottom. My DH has suffered for many years from panick attacks/anxiety and agoraphobia as well as a whole list of other things. We ended up having a very small wedding and didn't go on holidays for quite a few years. Now, if we go it's a big deal for him... Do you have any support from your GP, or does he see the community mental health team at all? It's important he gets medical help as well as support, although I appreciate that is really hard when you can barely get him out of the front door!
ok, lets tackle one thing at a time. Firstly, open curtains yourself, what is the worse that could happen? Secondly, regarding wedding your gonna have to be sneaky and forceful if this is something you really want to happen. I did this with my hubby who, like yours suffers really bad with anxiety and related stuff. I rang my local reg. office to book first appt to arrnage date and to show them our documents, ie, ID, etc, bascially we organised a very very small reg office wedding do in front of close family and friends and had a lunchtime meal, low cost wedding. Made my own bouquet, got cake myself, printed invites on pc. We had 21 days notice to wedding and cause of that my lovely man had no time to back out and get stressed see.
He will need to be lead by you in a loving but firm way to help him overcome his fears if you EVER want wedding and holidays etc.