New account but I played SL extensively back in late 2015 until about mid 2016, so my opinion might count for something.
I did get griefed some, namely on - you guessed it, sandboxes! But for the most part in didn't phase me. Second Life really is a lot like life. You'll meet a lot of crappy people and a lot of great people. The difference is that on SL anyone can hide behind a computer screen so the amount of griefers/idiots/drama queens seems to be slightly larger.
If you aren't having fun then you won't feel any better by making yourself play. SL should be a fun recreation, not a chore or something you dread to do. So, if you decide to quit I understand -- HOWEVER, if you hold out with the faith you'll eventually find the 'fun' in SL and the great people, then I think you'd be doing yourself a favor. Just let the griefers roll off your shoulders and keep exploring and doing you, that would be my advice. SL can be wonderful if you do so.