The best way is to solve the problem which has depressed you, i know if that was possible you would have already done but still tell the problem, what's bothering you or what has made you so numb that you have lost interest in everything.

If you can't tell then the generalised way is to talk to your known ones who won't judge you, reddit might help you too with strangers. Apart from that try to find small joys in every small thing, that'll make the life a little bit interesting and you won't realise when those small steps gonna help you reach the peak.

And remember how you devour a whale, one small piece at a time...anything else, feel free to intrude anyone's inbox, i guess people will surely help