Set point- Studies have shown that people quickly (within six months) to their normal state of happiness after a significant event. That thing that happened to you that made you depressed, there are lifelong consequences with some things, you will return to how you felt before. The same goes for that wonderful event that was going to make you happy for the rest of your life. You fall in love or win the lottery, those are great and may change your life, but you go back to the same level of satisfaction.
That does not mean, however, that you are doomed to be unhappy. The way you look at life is the way I looked at Algebra. When I was young, I did not like Algebra. I thought it was confusing. It sucked. Now perhaps, you feel that way about life. That’s because young people do not have the knowledge base to handle life (like I did not with Algebra).
Algebra may not get better for some of us. But it does get easier once you learn some ideas. I had a better outlook on Algebra once I mastered some of the concepts. The same with life. Young people, life does get better. You learn (from your mistakes). Once you learn things- life goes on, another person will love you, you must focus on appreciating what you have- you will get better at living and your attitude toward it will improve.
Each day, try to master the things that make people happy. You will increase your level of happiness. Bouts of depression will hit you. You will get sad, but with time (and maybe medication) you will eventually return to a level of happiness that people with money, fame or whatever don’t have.