Dear Hansaka,
yes you can start your education as a cook again. But i think you cant continue where you have stopped.
Maybe i have not all of Information for that but i think the "Agentur für Arbeit" wants everybody to help to get a new job so i think that shouldnt be a problem.
If you recieve money from the Arbeitsagentur i cant give you advise but i think too that they wouldnt stop to pay you because the Termination was indicated by mobbing you.
These are websites where you can find maybe a new employer
https://***.azubiyo.de/stellenmarkt/
https://jobboerse.arbeitsagentur.de/vamJB/stellenangeboteFinden.html?execution=e1s1&d_6827794_p=1