Your own job to do

I do realize that it is hard to say "NO" in case you get used to say "YES" for all those requests you had. Though, it is necessary for you to be skilful at saying "NO" as otherwise you will lose you life, you will live your life for other people but not for you. Realize, that you have your own life and your own time and the life and the time were provided for you only.
Those people also have their own time and have their own life and they can use those time and life for their own purposes, they can use those to do the entire job they have to do and they will also have time for their private stuff. You are good at doing your job and sparing time for your private life. So, why can't those people do the same?
Actually, they can and they do. The difference between you and them is that you do all those things on your own and you are skilful at managing your time in the right way. But those people made up better way to spare time to have fun – they have found out you and they let you deal with a good number of their troubles in order they had their time for fun.
Remember, you have your own job to do and you have your own life to live. And remember that you have the same 24 hours a day like they are and you have those for yourself. Tell those people that you have your own work to do and remind them that they have their own work and they receive their salary for the job they do.