late to this party, but I hear you, coach. no good deeds go unpunished in coaching!
If it makes you feel better, I coach JV HS girls, and at the end of practice one day I had them write down 10 things they did well in our 2.5 hour practice. It took them upwards of 20 minutes to come up with just 5-6 positive things. They could name about 50 negative things, or things to work on tomorrow, but they struggled hard with being positive. Keep your head up. You’re in the right place , doing the right thing!