I consistently find myself withdrawing from the outside world due to having anxiety problems/agoraphobic symptoms, depression and usually feeling very drained at having to spend time in the outside world especially if there are heaps of people around like crowds. I feel the most relaxed at home where it is calm and not unnecessarily noisy. When I had even worse anxiety problems than now back at the end of 2005/6, I tried to go places but found myself having panic attacks in shopping centres/with other people and crying whilst out, I would wake up of a morning and start crying and being physically sick at the thought of having to be part of the outside world. These days I have anxiety every single place I go, not to say some days are not okay, they can be, the anxiety-panic is not quite as bad as those days, not sure why... it might just be what your body/brain's going through at the time. But I still have a long long way to go before being healed or as much as possible, and am working on it by at least talking about it to people, hope one day all this icky stress and anxiety will give way to happiness as mostly I feel very numb/not happy/lethargic, it's pretty much a constant.
I have similar experiences to R (minus the crying... whilst out). The last time I had to withdraw was last month, but that was because I tore one of my thigh muscles and it was very painful to walk on it. Haven't quite healed all the way yet, so haven't ventured far from my front steps, but I think I will try in the upcoming week.
In the past, when it was a social thing, to bring myself out of it (and this may sound silly ) I created some symbolic necklaces for myself. My everyday one has a dragon holding a tiny crystal and a tribal spearhead symbol. I feel like it represents my normal beast and will and it's my default charm. The second one has a sword with the same tiny crystal and a tribal arrowhead symbol. I wear that one when I think my destination (or even journey) will involve a fight. Not always physical, but just when I think I will have to endure an encounter with someone(s) antagonizing. I feel it represents my will to fight back when I need to be fierce or ominous. The final one has a staff with a serpent wrapped around it holding the same crystal sphere as the other two and a tribal fishhook symbol. The staff with serpent reminds me of the similar medical symbol and the fishhook is to provide, so I wear that when I'm feeling ill or think I will need that little bit of extra strength to endure what I cannot fight but must survive. I'll probably be wearing that one next week because of my injured thigh. When I wear them and am out and I feel like I need a little boost to persevere I sometimes hold them, play with them, stroke them and wind up feeling a little bit better.