Thanks everyone, that's great advice.
Re: Davit. You're right that all my fears related to agoraphobia. This is actually something I semi-recently realized-or rather, admitted to myself--instead of just thinking of myself as claustrophobic. I think picking one I deal with the most is a great idea. I've been pretty lucky that I live only a 5 minute walk from work so I don't actually take the train or bus to work, so maybe working on one of those wouldn't be the most relevant.
One idea I did have was to do something related to being in an office--something that's a constant source of anxiety for me, and which I think if I could change would go a long way towards my happiness. Regularly I feel about a 30-40 when just sitting at my desk at work, but if I'm in a meeting this might go up to 60 or 70. Any ideas about something to do related to anxiety at the office? The only thing giving me pause about doing this for exposure work is that I basically do exposure work every day for 8 hours de facto just coming into work, so I'm not sure what to do different behavior-wise. Or maybe I should stick to something like a bus or train as practice?
Re: Ashley, that's a really good question. The simple answer is I want to do exposure work to stop feeling so damn anxious all the time. I can think of dozens of situations I'd like to reduce my anxiety in. But maybe if I'm being more specific, I'd like to reduce this the most at the office since I spend the most time here, and when I get home and think about doing something else that would produce some anxiety--like going to a restaurant with a friend--I'm often too mentally exhausted from a day's worth of exposure work.
Thanks everyone. This is my first foray into the forum and really appreciating the feedback and supportive community so far.