I live in Germany and rented two rooms in a residential community ("WG") for several years. Recently, someone who behaves very badly moved in. He destroyed many things, smokes inside, always listens to loud music, has loud fights with his girlfriend very frequently and at all times of the day (and night), is very aggressive, etc. The landlord terminated his contract after the tenant destroyed the entrance door ("Ordentliche Kündigung") and the same day terminated his contract immediately ("Außerordentliche Kündigung") after he physically attacked me and I told the landlord what happened and that I reported the other tenant to the police. That was on the 7th of April. But I already terminated my contract the night between the 2nd and 3rd of April because the problem tenant made it impossible for me to study and work. So my contract ends at the 30th of June. (Paragraph partially copied from this related question.)
I want to live in a different place because I don't feel safe here. However, when I canceled my contract, I made it a regular termination ("Ordentliche Kündigung") because I did not know how fast I could find a different place to live, especially given the Corona crises. That's why it only ends at the 30th of June. I have now found a new place where I could sign a contract (but would probably have to to so shortly so they don't pick someone else in the meantime).
Before I moved in, the landlord told me that he'd let me leave and stop paying him early when moving out provided I find a next tenant. However, he wants to renovate the flat once I moved out, so he doesn't want a next tenant. There is a 3rd tenant but he canceled his contract too (ending on the 30th of June, too). So to him that's great because now he can start renovating at the 1st of July. But he does not want me to find someone for 2 months because he thinks that anyone renting a place for 2 months will make trouble. He also does not want me to sublet my rooms for those 2 months.
The problem tenant still lives here. Can I terminate my contract immediately ("Außerordentliche Kündigung") as long as he still lives here, even though the landlord is trying to get rid of him? Is there an amount of time that he needs to keep living here until I can terminate immediately?