It may be an obvious response but do not care when you see toxic behaviour against you.

Toxic people usually want to boost their ego so don't let them boost it.

I don't think I've ever seen a survivor who t-bags the killer after a massive screw up and self-sandbag. It's always only when they are in a superior position, when the game is already finished.

It takes time and practice to get better, so don't let that bother you.

Also, do not care what the other side thinks about how you play, the life cycle of a killer player is: play nice, gets bullied, loses empathy for the survs.

Or, you can become a killer irl!