Welcome to the Wefugees community and thank you for your question.
Unfortunately, there is always the uncertainty that Ausländerbehörde might not prolong the Duldung. Even a work contract doesn't help in that case. You are now facing a tricky situation and there are a few things to keep in mind:
If you don't leave Germany "voluntarily" you might get deported and an entry ban will be imposed on you. The period of validity of said entry ban varies from case to case, but it is valid in the whole Schengen zone, so you won't be able to enter most of Europe as well.
That's why it can be a good idea to leave Germany within the one month notice that you've been given. You can apply for financial aid for that: http://www.bamf.de/EN/Rueckkehr/Rueckkehrprogramme/FoerderprogrammREAGGARP/foerderprogramm-reag-garp-node.html Note, that you don't have to go back to your home country. You can also try to go to a third country (keep in mind that you might need a visa).
Another option is the so-called "Kirchenasyl" which means that a church lets you live in their facilities. But this is just a short-term solution to bridge the time e.g. until you receive a residence permit etc. (so it only makes sense if you are having a chance to get a residence title another way than your asylum procedure). The church has to cover your living expenses and you won't be able to live a regular life because you can't leave the premises. You have to get in touch with the religious community in your citiy for this.
Finally, I wouldn't recommend to go into hiding and live in Germany "illegally". It's quite unlikely that your stay will get legalised at some point.
But I highly recommend that you get in contact with a counselling center or a lawyer that can take a closer look at your case. They might be able to show you options that I didn't consider. If you tell us where you live we can help you to find one of these.