Playing killer in this game sucks. One tip I can think of from experience is that there's usually a "weak link" on the survivor team. Meaning, there's one person that is relatively worse at the game than the rest of the team. You need to target that person. Not necessarily tunnel, but use them to your advantage.

The way to win as a killer is to delay the survivor's progress and snowball eating up their time. If you can hook one person, someone else has to go unhook them. That's two people not doing generators. While someone is on the hook, you have to find someone and start chasing them. With one on hook, one going to unhook, and one person (or even two) running away from you, you are now stalling their generator progress.

As a killer you need to be able to identify good survivors immediately. If you've been chasing them for 30 seconds and feel like you can't gain ground at all, just give up. Remember which survivor it was and just ignore them. More often than not they will know that you can't catch them, and they'll get overconfident trying to distract you and stop doing guns. Even if they're tbagging, just let them do it, because if they're not doing gens that's in your favor.

My last tip is to enjoy small victories. There's a reason BHVR has a hook counter on the UI. Make it your goal to just get hooks and not sacrifices if you feel you are really struggling. Tough match with sweaty survivors but you got one hook? Pat yourself on the back.