Employee wants to fire me because of the long wait for new work permit

I completely understand your stress. The problem here is whichever new employer you find, you might end up with the same issue with the paperwork. In other words, every new employer will have to wait for you to get that bijlage before you can start working (if I understood your situation correctly). Because of this, I would ask for legal advice, if you have some money to give for this, to see if speeding up the procedure is possible at all. ALTEA lawyers should be suitable for this. If you are out of the EU but have the right to travel through the EU freely and stay for 3 months, then I think you can stay even with no work permit or residence permit (e.g. like people from some countries like Serbia). Otherwise, as far as I know, BE does not allow people to stay if there is no apparent legal reason for this (e.g. after studies, there is no so-called "orientation year" to look for work like in Holland etc.). Anyhow, paying 100-200 eur per h for a consultation with a lawyer might be a good thing to do.  You can also try to negotiate some agreement with the consulting company that would fit both. Good luck!