everything is changing, if he/she doesn't like you or doesn't want to be with you anymore. don't wait to waste your time, just let it go. and the most important thing is that you have to move on, you have a life waiting for you. he/she won't come back to you if you are still living in the past, cuz he/she leaves you cuz of that. therefore, what you can do is to move on, maybe he/she will be back to you one day, although he/she is not the same one anymore.
do whatever can make you happy, just do it. don't tell me that you are only happy when he/she is back to you. that won't happen......let it go.......
good luck!