I loved a girl but I didn't told her now I am depressed please tell me how can I motivate myself and move on?

[Yotth]

[Effably]

One foot in front of the other.

Taking action, any action, is typically better than none. Go for a jog. Do some exercise. Starting simple and making yourself do stuff - every day- is really how you break out of depression. It isn't easy per say, but what stops you from a brisk walk or something?

As for the girl, shame. But it is good experience to have for you. Next time you'll do a little better a little easier.