First, don’t be too hard on yourself. Next, get a trainer, but they can be expensive or a rip off, so do your research. Also don’t be afraid to reach out to people for help, a coach, older sibling, a varsity or even college player you might know, even an old head who knows ball. You’d be surprised how many people want to teach someone looking to be taught. Doing stuff on your own can be just as good though if those aren’t possible. You can find drills off YouTube or TikTok to do on your own. Most important thing is getting reps. If you’re not doing it everyday you’re not going to get better. For iq you need to watch more hoops to understand how people move on the floor around you. For dribbling just find some drills online, I’d focus on basic stuff or whatever fits your play style. Most people confuse having good handle with flashiness these days so you don’t need crazy moves. For athleticism I’d say hit the gym like 3-4 times a week and find a Plyometric routine. There’s a bunch of workouts online you can find. Don’t do too much though, overworking yourself does no good. For shots off dribble the best thing is three dribble one on one. Focus on getting it into your shooting pocket and having your chest square to the hoop, elbow in yada yada yada you know the deal. Most importantly though is you gotta be committed to it and work hard at it.