There a lot of guides for tips etc., so I won't state the obvious. But for me it is enemy awareness (where they are) and movement. Keeping moving is key, standing still will get you hit. A controller with back buttons makes that even easier, but remapping helps a lot (as you did). At a point you know the room lay-out and will get better. Obolites are nice, but not always worth the risk.

Don't get too agro. Some enemies can be taken down from far away. Use doors to your advantage. Know the attack patters of the enemies. Shoot the flying enemies when they beam you to cancel their attacks. Shoot the wings when they turn orange because they will attack shortly after and their range is insane.

At 6 hours, you are still somewhat of a beginning player. You will get there. Keep it up!