Our problems begin in the mind and can be solved in the mind. Often the reason for your sadness, anger or negativity is the way you think. You have to take control of your thought process. If you change your way of thinking, you can better manage the issues troubling you. It's not the situation, it's your interpretation of the situation that gives you stress. Prophet Yusuf was never angry at his step-brothers because he thought: my brothers are not evil, rather it was Satan who made them act against me.
also we should learn to tolerate every situation and to forgive.. If you remind yourself of a negative experience from your past, you make it more powerful and store it up in your mind. You need to forget your bitter memories so that you can see the new opportunities in front of you. Your mind will not be full of sad thoughts, but it will be free to think and achieve something great. This is why, the Quran tells us to forget people's bad behaviour with kind forgiveness.
Another point to be noticed is that the Prophet, peace be upon him, has said a kind word is charity. So many times we speak rudely with people, say hurtful words and care only about our own feelings. The culture that the Quran wants to create is to give to people even if they don't give back. This means being gentle, showing sympathy and having a big-heart even when others behave differently. Often we complain why others are treating us badly. Islam requires you to focus on your character and behaviour, not blame others or let their behaviour influence you.