Since then I have been airing the room like a maniac, I tried treating the window sealings with vinegar and later with hydrogen peroxide (bleach doesn't kill black mould, apparently), but I think I probably just made the problem worse by scrubbing and releasing spores into the air.
I manically try to follow all the advice on the internet, which mainly boils down to ventilation and temperature control, but almost every day I find something else I hold dear (my favourite t-shirt... my leather office chair...) that was attacked by the mould.
At this point, my main focus is to vacate this goddamn place as soon as possible, costs what it costs, because I am terrified that more of my belongings will get damaged, and it's affecting my health as well (irritated eyes, itching, asthma symptoms). Or does anyone have a better idea? I am not on the lease, I have an Untermietvertrag with the tenant of the other room in the flat, who so far turned out to be really unhelpful.
The sublet contract has a notice period of 3 months (to the end of the month). If I move out before this deadline due to the mould problem, would I have to pay the full rent until the end of the notice period? Again, my contract is with the other tenant, who in turn has a contract with Von Graffenried, who are blaming the previous tenant for the mould problem?
The other part of the problem is, how do I find an escape route really quickly? After this adventure, I decided I'm not taking any more risks with flatshares and would prefer renting on my own. I have been to viewings and applied for flats, but I don't seem to be getting anything and I think it has to do with the fact that while I'm on a high salary, I only have a temp contract at work. And like I said, the issue is becoming more and more urgent by the day.
Many thanks in advance for any constructive and helpful replies!