I have to move out my flat due to safety reasons but I can only send my one-month's notice on the 20th. I can't afford renting two rooms at once. (London)

I moved into my new flat in London on the 30th of June.

Yesterday I had some issues with the only male flatmate in our house (who I'd just met that day), who shouted and screamed at me for cleaning a past tenant's rubbish, threatened me by throwing something at my door, and later that evening tried to intimidate the other flatmates and me by recording us and threatening to send it to our landlord. Due to this, I no longer feel safe in the flat, and I texted my landlord explaining the situation. He said he'd talk to him, but despite this, I've made my decision and want to move out.

However, because of the renter's rights, etc. I can't put in my one-month notice until the 20th, which is quite far away. I am quite desperate to leave, as I feel like I am walking on eggshells around him, never knowing when and if he'd send a passive-aggressive text for the smallest amount of dirty dishes, or shout at me again for no good reason.

I understand that I can physically move out at any time; I just have to pay this month's rent and then put my notice after that, but I have no friends or family to stay with, as I know no one in London (I just moved here from somewhere quite far away). So, I considered just renting another flat and moving in there, and then giving the landlord the key to my old flat once my tenancy ends.

However, I am a uni student on a placement year. I cannot afford to rent two rooms at once. But I am so desperate to move away, I haven't eaten proper food in days, I am so stressed I'm breaking out, and I feel scared to even exit my room. I'm ~300 pounds in overdraft already because of June's rent, and I'd reach beyond max overdraft if I paid for both this room's rent and the other's security, holding deposit and first month's rent, too.

I have no idea what to do; I'm stumped. And no, I can't just "suck it up"; I'm a 20-year-old woman, and I was threatened by a man in his 30s. I am not safe/comfortable here as long as he's living here. And no, I don't think he'll be kicked out anytime soon. At least I think my landlord wants to give him another chance, but I am not going to wait around for something else to happen.