This game is extremely easy... Not the hit-box is extremely small and there are visible gaps all over the screen all the time. Bullets are beyond easy to graze and getting extra lives is like stealing candy from a baby.
Cover the entire screen with no friction, let go of the mouse, raise the friction slightly until the the lights begin to dim, then completely get rid of the friction. It creates a black space like void of dimmed particles. It looks cool.
Hey, Otaku_7768, there's a passive skill on the psychological skill tree that takes 10% of your own HP every turn, in return it doubles the potency of your HoTs, and DoTs. The skill is called "Overdrive", and starts on the top with "Terrify." I'm assuming that's what's damaging you.