Are you familiar with Cognitive-Behavioural Therapy (CBT)?

Try to become aware of your thoughts. Especially notice if you were feeling okay/not too bad, and then something happened and you started feeling unhappy. The idea is to then try to replay the barely conscious thoughts you had in response to the thing that happened, and see if they were really fair on you or were they very negative?

Many of us have learnt negative thinking patterns and they become so ingrained in us that we automatically negatively evaluate every challenge that pops up, and often foresee loss, failure or misery for ourselves. These thoughts are totally unrealistic though, and it doesn't take long to see that when you start to consciously scrutinise them.

Meditation can really help with giving you relief from psychological pain, and also helps you to become better at catching your thoughts.

Also, if you haven't already, find something larger than yourself to be identified with.

If you don't make progress soon, try to see a CBT therapist. They'll teach you practical techniques for changing negative thinking patterns and core beliefs about yourself.