How the hell do you beat this game?

Every run i do i get smoked on floor 14, running out of potions and being swarmed by brutes and if i dont die there i die earlier to either skeletons or fly swarms.

Im stuck with the base weapon until the first boss and get ruined and it's just frustrating. Ive played well over 50 games and im just being ruined on each one because it constantly whittles me down until i run out of every reasource.

What do i do?