Specifically since this person mentions that he's "active, extraverted [sic] and social." Which is not to say that such people will always hate working alone, or that people who enjoy it can't be those things, but it seems from his description that working alone is something he probably should have avoided or, now that that's impossible, do something to change.

I think the coworking environment in another comment is a great suggestion in that vein. Having worked in one of them for the better part of a year, for people who really just want to be around others while working, that's pretty ideal (aside from the relatively minor expense, but if that's something that's going to make you significantly happier, it seems likely to me that you could find one with a cost that makes it viable and worthwhile).

Edit: I've also been working from home, alone (cue Macauly Culkin), for years and love it.