Are you having fun?
If you are not having fun, seriously consider the possibility that you are a jerk.*
If improv isn't fun, it probably has to do with judgment. You're judging other players, judging yourself, or judging your coach. Judgment is antithetical to acceptance, to YesAnd. In my head, this idea looks something like:
The solution to not having fun is to have fun. That means showing up** and playing with your fellow artistic geniuses. Having fun doesn't mean everything will be easy, but who cares if it's easy if you're having fun?
Even if everyone else really is better than you, have fun. If you're having fun, nobody will notice your shortcomings, and you'll get better faster.
Even if one of your troupe members really is a black hole of comedy, have fun. If you support them anyway, you might be surprised. And even if you're not surprised, this scene is over in three minutes, so who cares?
Even if you think your coach is trying to ruin your life by turning your troupe into an extension of his own ego, have fun. Play hard despite your director having an off night or your coach asking you to exercise a muscle you don't feel like exercising.
I know these blue boxes well because I have been guilty of all of them at different times. When I was stuck in that orange box, it had less to do with improv and more to do with how sick and depressed I was at the time. Talking to my coaches about it helped.
If you're in that green box, can I come to your shows? Better yet, can I play with you?
*Credit to Derek, who got me started on this train of thought a few years ago when I overheard him say something like this to a surly workshop. Susan Messing and Rachel Mason both say things along the same lines, but they are less quotable for being rated R.
**Physical presence without emotional presence doesn't count.