@Ninie You can't think you way out of this problem. You must make a distinction between thinking this stuff and observation of actuality. Less thinking, more observation is necessary. Learn to sit and observe without emotionally reacting to anything at all. Stop judging things, stop fantasizing about the future or the past. Stop thinking about yourself. Stop thinking about your life. Just sit and observe the present moment. In the present moment there is nothing sad or bad.
Start to notice when you are conscious vs when you are reacting emotionally to anything at all.