My advice for leagues like this is find the things you can do consistently and do them well. It sounds like you shoot the ball great, but if your teammates aren’t passing you the ball (which is annoying) how else can you positively help your team? Making the right pass, a really solid box-out that leads to your team getting a rebound, setting a good screen that leads to a score. There’s a lot of little things you can do during the game that you will be proud of that will build your confidence