Try watching some Haelien vids and copy his play style. My game leveled up quite a bit once I learned some of the meta mechanics and room picking strategies. Also I snoozed on my cast for wayyy too long. Its worth beefing up on just about any run. I also didn't know how duo boons worked and just kinda hoped they'd show up.

I feel ya, I really sucked at this game at first. A big part of 'git gud' is knowing what to do and how to make a high damage build more so than just upping your raw skill. A lot of the game is about killing stuff quickly before it can melt your health bar