Hey, I'm really sorry you're going through this. A lot of people have already given some great suggestions. Operating off of my own experience with similar situations and needing to earn a lot of money in a very short period to cover bills-
1) Do you know exactly how much you'll need to cover living expenses until the 4th? If not, the first thing to do, if you haven't already, is to calculate exactly how much you're going to need. Sit down, take a deep breath, and write a list of the things you will need to survive until then. Food, medicine, utility bills, phone/internet- try to think of everything you can. If you've been working with this bureau through a social worker, I'm going to guess you've probably had to make a list similar to this at some point for tax/grant/benefit programs of some kind (I don't live in Finland, so can't say for sure), so you may have something to reference. I know this may seem like an obvious thing to suggest, but I also know what it's like to panic in a bad situation, and sometimes we just don't think logically.
2) Once you've converted your list into a number- try to think of all the ways you can get any things on that list for cheaper, or possibly free. Food is a good example, especially during this season, when there are a lot of special food drives and similar initiatives going on around the world. Churches/other religious denomination buildings like Mosques and Synagogues, universities/colleges, hospitals, local community organizations- they all have programs you may be able to access just by walking in. If you have to access resources typically intended for people struggling with homelessness, this is not a reason to be ashamed. Those resources exist precisely because people end up in these kinds of situations. Their purpose is to help you get through them. Also, to use a personal example- I would sometimes visit free open gallery shows and college speaker events that have food tables just to get a sandwich- questionable ethics perhaps, but it works. In fact, many non-profit organizations and religious groups offer meet-ups for certain segments of the local community organized around an event or movie night, operating on the assumption that most people who come to the event will be there mostly because they need food.
3) Of course there will be things left over you have to pay for, no matter what. If you are having trouble getting commissions online and/or can't do them right now because you don't have a tablet- what are the laws for busking where you live? I have gone out and offered portrait drawings on the street before without any kind of license. Believe me, your traditional art is definitely of sufficient quality for this! If there are any nearby fairs going on, you can ask them if they'd let you have a place- maybe even share a tent with someone, if it's outdoors. I understand that with your social anxiety this may be especially difficult, but it may be worth thinking about if you're willing to take commissions in general. Other people have already mentioned short-term jobs. You can earn some money replying to online internet ads for something that just needs to get done that day- often manual labour or temporary care/cooking and chores for someone who requires it.
If the biggest hurdle to earning money right now is having to interact with other people, especially strangers, in person, here are some other options that require minimal interaction:
-replying to online requests for ghostwriters, basic document formatting and photo editing work (depending on what software you use- but you probably won't need a tablet for that)
-postering/flyer circulation jobs. Often a one time gig. Universities, certain big companies and non-profit organizations are likely to be looking for people to silently go around a town putting up posters and leaving flyers in strategic locations all the time. You don't really have to interact with anyone, except to get the job itself- and even that can often be done online or by calling.
-online art commissions are definitely hard to get, sometimes even with a larger following if your followers aren't very responsive and have little disposable income. So far, I've noticed Twitter seems to have one of the most responsive communities when artists post about emergency commissions. If you feel anxious about posting content to an audience of one- why not open an account and share it here, so we can all follow you and share your commission page? I'm willing to bet everyone who responded to your query on this forum would be willing to follow you and share your post! <3 And if you aren't able to fill the commissions until January because of a broken tablet- would it be possible for you to use a friend's working tablet at some point? I've been in this position before and had to ask friends if I could borrow their work space for a couple of hours. They might be more responsive than you think! (especially considering you are doing this so you can earn money to live on, and many people are taking a break from their work to visit family right now)
I hope that helps, @Mari - if you want to DM me to talk, I'd happily offer what further help I can.
P.S. One last thing. I've known places like the bureau you're talking about (in other countries, admittedly) speaking as though you've got no options and you have to pay up or get a lawyer. Frankly, sometimes that's just a receptionist talking out their ass to get rid of you as soon as possible. I can't speak to your exact situation, but there have been times where I've had to deal with a department of a faceless organization like this just by annoying the hell out of them with incessant calling and showing up at their offices until they realize they won't get rid of me until they do something to help. If you do decide to try this though- bring a friend, because it's exhausting and emotionally taxing. People will get angry and tell you you're a nuisance, and quite possibly far ruder things- but if you bear through it, and show you're not letting them walk over you just because you're somebody's "inconvenience"- it may solve the problem for good.