I find that helping people, just for the sake of God, to be therapeutic.
An Honoured Station
Expect nothing in return except for the ability to serve. Ask God for that. Ask Him to make us servants - servants of the people. Ask Him to put us in the position of service. Honestly, the position of service is an honourable position in the sight of God.
The Prophets were servants - they served their people and they ultimately served God.
Those who serve others are following the footsteps of the Prophets, and really, whose footsteps are better than those of the Prophets?
A Path to Contentment
When you serve others, you are stepping into worlds beyond your own. In effect, those whom you served are stepping into yours too. This sharing of worlds is more than an exchange in perceptions, rather an expansion of perceptions.
You start to realize that the problems that you personally have aren't that bad. You start to realize how big the world is, with its infinite possibilities. The world is not bleak and gloom as you might have thought before.
So if you ever feel down, help people. They could be your family, friends, or strangers in the streets.
Your problems aren't the end of the world. There are others who are experiencing worse. Out of this understanding, you start to feel thankful.
A Sense of Responsibility
It's not enough to say thanks with your words to express thankfulness, but it's a start. Thankfulness should motivate you to act, to use those blessings you have in your hands and spread them to other people.
Find every opportunity in your life to do that. Find every opportunity to help. Utilize your life for service.
The best of people are those who are beneficial to the society.
Ask God to make you a servant, because to be able to serve others, in and of itself, is a great blessing.
Alhamdulillah. Praise be to God.