I agree with your coach.
Pushing will get you so far even if you win a lot at lower levels. Confidence he may have shot down now is better than going up a level and not understanding why you are always on the defense. I know this all too well, cause ever since i came back.. i tend to get trapped playing lower level peeps,.. and just need to keep the ball in play to win. I later go to nationals and have my hands full. Wasn't like that back in the day where I went for my shots.
Invest in your shots. I'm not saying bang it, but step in.. go for the shot.. don't just chip it in and be tentative. If you feel you are holding back.. then you are definetly not improving. You are being safe and comfortable. If thats what you like.. I suggest to me that the public park weekend play is your ultimate goal.