First Checkup (15K), Help me figure out why I suck....

[2+2 Junkie]

Ok, trying to get the consensus here:

Pre-flop is pretty good, nothing out of the ordinary.
I need to be more agressive post-flop, will need help figuring that out, look forward to posting hands for that help.
It has been suggested that I am folding too many winners. Is my went to showdown OK? If so, am I taking the wrong hands to showdown? I thought that my winning % was OK, but does it need to be lower? If so, how does losing more hands help me win money? Please explain.

Also, are there any other stats that one might need to better understand the situation?

Thanks as always.