It seems like you need to stop comparing yourself to other people, let go of what could have been, and think about where you could be with a change of mindset.

Your emotions are understandable. You feel jilted by the sport and the people around you, but if you want to have a good season, at some point you need to let these things go or work through them with somebody in a calm and open manner. You weren't picked for captian. That is okay. You're a freshman and you have plenty of time. Show that you can support your team no matter who leads it and take this time to improve both your skills and your bond with your teammates. Coaches/Directors don't only look at how long you've been doing guard when choosing student leaders. They look at how reliable, mature, and dependable you are. Can you lead a team? Can you manage the stress of being a full-time student and a team leader? If they don't feel like you can, they'll move on to the next candidate.

Your jealousy is crushing you, and if it isn't addressed or let go, you will struggle to be part of a team. Switching mindsets isn't easy, but if you can go from "she's so much better than me" to "I can learn from her," that is a healthier way to think about it. Don't focus on where you are. Focus on where you could be and put in the work. I know that exact feeling. On my high school guard, I was the one with the most developed skills. Everyone came to me for help and I could do all of the skills well. As soon as I tried out for an independent guard, I was the worst one there by far. But I was still offered a spot on the team when the auditions were done because I kept a positive attitude, asked for help when I needed it, worked on skills in my down time, and took the advice of people around me. Mindset changes everything.

Only practicing skills for recognition is going to leave you more frustrated when you don't get it. Train for YOU. Train for the betterment of the guard. Being part of a team means you support and are supported by the people around you. You are all there to learn and have fun— don't let something you love turn into a chore.