Whenever you feel like not being able to escape a state of unhappiness, try practicing the so-called retrospective judgment, which will enable you to reinterpret the events lived in order to find what was good in them.
Practicing story-telling when it comes to your life can prove very useful and healthy.

Give yourself a story you can live with

Professions like the ones in accounting and law develop a sense of pessimism in the individuals practicing them. However, being obsessed with prudence at work and continue being like this at home is not quite the same thing. 
Furthermore, training your mind to stop being focused on finding mistakes is something that will save you some good headaches over the years.

Educate your mind to stop being unhappy

While comparing yourself to others might not be extremely helpful, comparing yourself to people who are in a less good position than you might actually lead to you feeling better. 
So, if you really feel this need, try not comparing yourself but to the ones in an inferior position.

Social comparison

In order to be happy, you must first train your brain to perceive the good that happens to you. 
One way to do this is by writing down three good experiences you live on a daily basis: appreciation comes from within, just like happiness.