Basketball workouts and mentality

Question
Hello, I am a 14 (going on 15 in 3 months) freshmen about to be a sophmore in highschool.  I have been playing ball seriously since 6th grd and i have recently gotten pretty good since last summer.  I was set to try out for my highschool's JV team and I made the summer league team.  I didnt play alot becuase of my mentallity in the game.  At a park or rec center i would play pretty well but then in a regulation game i would play like an amature or below level.    I couldn't get to the basket, my left hand dribbling wasn't great and i just didnt know what to do out on the court.  I hate it because no matter how much i practiced it wouldnt work out in in game situations.  I guess i was scared or thought too much or just wasn't experienced enough.  My first question is, how do i overcome this, be a standout player and play at my best in a real game.  My second question is about working out with weights.  I had (last summer when i was in the JV summer league) had had a decent game/shot.  But then that summer the coaches wanted us to do basketball workouts in the weight room.  This greatly affected my shot and as a result i made the fall league but was benched becuase of my poor performence.  I think one of the things about working out was the fact that it made my arms feel tightened up (not loose so i the shot didnt feel right).  My shot was ruined, and I think, it was a result of those work outs.  Now, after the season my game improved much but still my mentality lacks.  I have recently, last week worked out and my shot is off the mark again.  I had a decent inside game but i couldn't shoot three's for my life.  I lossed that inside/mid range shot.  I want to do football too so that my agression in basketball can be better and so i can get into shape with the workouts.  That means i will have to work out alot more and might not have alot of time to play ball.  First and fore most I love basketball more than any other sport and am very serious about it.  Like the millions of ballers around the world I want to be one of the best but these things are holding me back.  Should I continue these workouts when they mess up my shot and when i am at a young age?  I am also afraid i have stoped growing as a result of the workouts, im 5'8/ 5'7, already taller than my parents who are 5'2 (mother) and 5'6 (father) my grandfather was said to be 5'10.  Is there a way to work out and still have my shot (becuase my coaches want me to work out and i would like to make them happy).  And also could you please tell me how i can perform better in a real game (mentality, etc).  I've sat the bench my whole life and i want to step up and be the best.  Please give me advice for my problems.

Answer
Omar,
First of all, the workouts aren't what's affecting your shot. It may take you a little time to get use to it but it's common to be able to shoot jumpers after working out. There are players in college and the NBA who workout before practice or games and their shot is just fine. You need to start working out on a regular basis( three times a week)and your body will adjust. The key is to try and get some shots up right after you finish lifting. Shoot until your arms feel good again. Your biggest problem is your mentality. You're putting way too much pressure on yourself. Basketball is suppose to be fun. You're suppose to be playing because you love the game. You need to take some time out and remember why you started playing in the first place. Stop worrying about HOW you're going to play and just play. Enjoy the game. Continue working hard and stop thinking about it so much and it will come. Oh yeah, playing football is not going to make you aggressive. That's something that has to come from within. Plus, you need to learn how to be aggressive on the basketball court which is different from being aggressive on the football field. I would suggest that you don't waste your time playing football. If basketball is what you love then that's what you need to do. If you want to be one of the best, don't waste your time on the football field when you can be in the gym. Good Luck!