The average run is what you think is average. People in the speedrun community all have different standards, there's no real answer to this really. :P

Or, alternitivly, when would you advise a reset? I get discouraged very easily tbh but I reckon when there is no time save or no chance of PB.

It's all on you to decide when to reset. Usually the rule is if you absolutely run out of time to save, and you're so far behind that the +time can't be made up, then you reset, but sometimes, and I've seen this happen, if you don't reset you can end up pushing yourself to finish with a small PB, which is better than nothing.

my last NG+ run should have been a 56 but i choked it away, still saveed 4 seconds overall though