This can really burn if you're in a position of not having much/any current income, but I think in general selling is more often NOT worth it than worth it, especially from an uncluttering/decluttering point of view (which is part of why I can often be found griping about 'frugal' being conflated with 'uncluttered' as it sometimes is even in this forum, but that's neither here nor there :-)
Aside from all the reasons others listed, there's another one: it takes a lot of hassle and a fair bit of knowledge (of the market, your selling venue, etc) to make money out of selling used goods from a private collection, which means that usually making money from that may help unclutter your home, but it will clutter up your time. And even if you're not currently in formal employment, your time is still the most precious thing - it does NOT pay to waste it doing things that give you low returns for high investment any more than it would if you were a busy CEO of a fortune 500 (actually, maybe even less than them). Specifically, in your case, looking for employment like I'm sure you already are comes first, and when you're not doing that or fulfilling other obligations eg taking care of dependents, taking the time to take care of yourself and recharge so that you may be more effective for the aforementioned tasks must take precedence.
Finishing with the day's job search, going to pick up the kids and feed them, then settling down to scramble to make money off of low-to-mid-range stuff that's already used instead of sinking into a hot bath, going for a brisk walk or reading a book is probably not a good investment of your time OR your energies in this difficult time, in that it is unlikely to net more than basically pocket money - enough for some temporary relief, but not a solution to your income issues proportional to the time and effort put in.
