How to Be Happy (Or At Least Less Sad)

I have been trying my best to be happy, or like the title suggests, at least less sad. I've been trying to make new friends, meet new people, meet with old friends. Something I also need is a new hobby. Should I go back to writing? Save money so that I can take martial arts again? I need something to do so that I don't go crazy or go into a deep depression again. I don't want to be sad all the time. I am not going to be blamed or feel guilty every day for the rest of my life. I won't do it. So what things do I need to change in my life? My not so active lifestyle? My job? My person? I want to work things out, but I also know that some things, no matter how hard you try, can't be fixed. At what point do you just give up and decide to start over? I need to go on a trip by myself. I need clarity. I need me time. I think I deserve to have some me time. I want to be myself again. I want to be happy, laughing, silly Kristina again.