Let them know their beloved man that, despite everything, you believe in his ability to solve everything and get out of any situation. Your confidence will RUB off on him, and that thanks to this support, he will feel energized and find a way out of the situation.
If you know how to solve the problem faced by your young man, offer him the best path to its solution. However, it is best not to talk out of the situation "in a forehead". Try to bring him to the right decision delicately hints – it will be better to think that he coped with their worries.
Tirelessly remind him that he's the smartest, and any decisions he took, will be the only true. Thus man will cease to be tormented by doubts and act more confident.
If you know the root of the problem, nothing prevents you to invent or to bring a real case of life (or their mutual friends), as in a similar situation have been known to his people. One of the most effective ways to cheer him up will be a corresponding online article (newspaper, magazine), which provides instructions on how to act in a given situation.
Throughout the time that your loved one spends in depression, thoughts, etc., be more attentive to him. Try to read his mind and understand what he wants. Do not forget about the domestic side of the question – a man should always be delicious food, a warm bed and... sexy girlfriend life. All this will help him to switch and remember about the earthly pleasures available to him at any time.
In no case do not succumb to depression themselves. If you are not going to emit positive, your second half will go more deeper, surviving twice: now, not only for themselves but also for you.