Whatever your vision is for what will satisfy you, you will work towards that. Passion and discipline for that thing will be easier. If you don’t truly believe something will lead to joy and life, you won’t ever really go after it. You will have no passion, and discipline will be difficult.
Thus, if you want to change, start with changing your vision of where you will find life. But how do you change your vision?
You ask God for a vision and seek it from him with your whole heart. You seek the answer from scripture. Ask your wise friends. Also, belief is static. It is always changing. You need to keep believing, which takes effort. You need to continue rejecting lies and embracing the truth.