Stop saying Yes when you mean No

Most of the time we change ourselves to make others happy, and later on we resent them for that which cause nuisance, then why actually we can't express ourselves truly on that moment. You know why because we try to manipulate people's reaction in our favor, and wants to look good in their eyes, but no matter what you do. If someone is evil then he won't be giving any damn about your deeds, and because of this weakness, of not saying the truth. Which means your heart felt something, and your tongue says something will cause you lot of trouble later, so say no because you don't need to fulfil someone chores by making yourself miserable. Instead of that be yourself, and let right people love the real you.Which will eventually make you ecstatic, and remember before going kind for everyone else. First become kind to yourself.