I do not know if this will help, but whenever I find myself falling into unhappiness and depression, I try to find something that I love or that makes happy and do that. I force myself if I have to, even if I don’t feel like it. I go for walks in the woods, work on an art project, read, ect… That’s the trick—making yourself think about positive things instead of waiting to feel positive things.
If I am upset about a situation, I force myself to look at the situation objectively/logically and then find something good about the situation. If I am angry at a person, I try to see the situation from their point of view and forgive them. Whenever I am most depressed and angry, it is because I am holding on to my anger as proof of my ‘rightness’ in an argument. I hold on to anger as a shield to protect me from other people’s anger, ridicule, cruelty, and condescnetion. But in the end, I suffer more than the other person because it is I who has to sit in depression and I who believes that other people’s remorse and suffering will somehow bring me happiness. I have found that if I try to truly understand other’s points of view (really try, not just a strawperson view that belittles their view), then I am much happier because I find that I want them to be happy, and wanting others to be happy makes me happy. If I can let go of being afraid of other people, then I can be happier and thus be more kind and loving to the other people around me, and then they in turn will be more kind to me. And if they’re not, then I will have the stregnth to not be afraid of them and stand up to them, not in anger, but calmly to work out a problem. It all starts will just consciously and logically deciding to not be afraid anymore and to be happy. Tell yourself that you are a good person. You are a person worthy of being loved. Name all the things in the world that are wonderful. Name 100 things. Name 1000 things if you have to! It all starts with thoughts.
If the people around you are drags to be around, then try to be around people who make you happy or find hobbies that make you happy and meet people who enjoy those hobbies. If that is not an option at this point in tiem for you, then always remember that they cannot do anything to hurt you. They cannot do anything to stop you from being happy. They can say or do mean things, but you are solely in control of your own thoughts.
I think that happiness is something becomes a habit like anything else if you force yourself to consciously make efforts to think thoughts that will make you happy, then you will eventually become happy. Our brains are wired so that we become what we perpetually teach ourselves to be.
I hope that helps, even if just a little. :)