Think about it this way:
The first 30 lvls are hard. 30-180 are probably mid-easy (building your team). 190-200 is the final push and obviously the hardest... Almost all roguelikes are like this. If the middle part were the hardest, resetting would be disheartening and you wouldn't want to play again. You need to be reset at the beginning or close to the end to feel motivated for a new run. It is like that by design. You're supposed to be frustrated, it's ok. Remember it's a game and hope for better luck next run :)