If you can't become a soldier, then go out. No matter what you do, you must find a way to go out for exercise. Society is very complicated and wonderful. It is a big vat, a forging furnace. Maybe you will suffer, get hurt and become a tragedy, but it may also bring you happiness. The most important thing is to stay in the society for a few more years and you will find out where your life goal is!
I suggest you ask your parents first and ask their opinions. Will you leave you at home? You are still so young, you can go out for a few years and talk about something else. Larks can never fly freely in the sky unless they learn to fall first. You should tell your parents your worries, communicate more and understand more. Let them know what you want in your heart, and let them know whether you can grow up by keeping you at home like a canary. When you are young, you suffer more, but when you grow up, you will be blessed. This is called experience. So that when the time comes, when you grow up, you will collapse and your life will be bleak.