How to be cool in irritating and consuming situations

                        I have heard some dialogue in a serial named The Arrow. It says, "The pain is inevitable, but suffering is optional."   When I was through some what difficult situations, I used to think very bad and I used to disturb myself so much. I used to feel irritated and the consequences like fights with friends,  lack of sleep, disturbed mood are obvious. But after listening to the dialogue, whenever i am going through any difficult situation, I started thinking that unless and until you wish to suffer, you won't suffer.
                      For example, if one of my friends is not behaving well to me or ignoring me, I know it feels bad, but i have option to choose between the continuing to feel bad and just move on to some other things like talking to another friend, watching something, eating, or any other sort of entertainment or useful work. So I decided to choose any other thing other than feeling bad and hurting myself.