There is the possibility you’re not good enough. But you have to start asking yourself questions.
How badly do you want it? Do you prefer to play or do you want it?
Are you the first to arrive and the last to leave every practice? Do you compete in every practice like it’s the 7th game of the World Series?
What are you doing in the off-season to improve your skills? What are you doing in the off-season to improve yourself physically? Have you made yourself as physically as big, strong and fast as you can be?
You don’t get to college ball on a prayer. You have to put yourself in the right place to gain exposure. If you’ve thought about quitting high school ball you don’t have the motivation to play college ball. It sounds more like you prefer it than want it.
The coach told you you’re not good enough. Did you ask him what you need to improve to earn a position?
You haven’t had the chance as a pitcher? Who is stopping you from improving your velocity? Your mechanics? Do you even know if you have quality mechanics? If you show up throwing harder and with better command than other pitchers on the sidelines you will be put in the game.