youth is a big problem, just 3 upperclassmen. So you have the poor IQs to deal with along with the abundance of overhead room for improvement from most of your guys.
But another issue is that it's not a great FCP kind of team. ATH and SP are just meh, and the stamina is pretty poor to be honest. Outside of Paramore and his 93 ST (off the bench I might add), your team's overall ST is ~70. The stamina of your highest starters is just 77, and 2 guys have this. And you're compounding this issue by playing uptempo in all your games. Not good. I'm seeing plenty of shades of yellow and worse in the stamina boxes in your games. Not good. You're also committing 5 more fouls a game than your opponent, probably a byproduct of the poor stamina and the hacking at the end of games when you're losing I'm sure. But the stamina issues probably affect your FG% more than you realize.
Lastly, Self is certainly underperforming, but I'd be running more of my offense through him and England, esp. given your youth. I try not to rely on my freshmen and sophs too much unless they've proved to me they deserve a higher distro.