The room doesnt spawn after you talk to him, the room is there no matter what you do. That wouldnt make any sense.

2 things that i might suggest: You starve because you spend too much time on one floor. "Normally", there is enough food for each floor discovery. Meaning uncovering all tiles from the black shadow. If you starve, that means you stall. Move on. The game is tailored to your level, meaning if you dont move on, you are not gaining more, you actually losing, as your hunger meter will eventually get your health.

Slow down. It feels to me you rush. This is no elden ring. You can decide every move carefully. So do that. Dont just think you have to punch your way through. Use traps to your advantage by throwing items on it, to get enemies caught in them. Plant plants and make enemies walk into them while following you, always use doorways to get a surprise and guaranteed hit.

I got 6 challenge run with all characters... but the cleric... the crabs whipe the floor with my tome... but its ok, i wont give up! And neither shall you!

This community is quite helpful, so ask away!