I'm sorry for your loss. He was young and full of life, very difficult to understand how depression could overtake a life.
Take it one day at a time, accept your confusion, cry, talk, or just laugh at the good times you shared. That video was a great expression and celebration of his life. Your sense of humour can be a great tool at any hard time. It is OK to laugh at things you would usually laugh at, it will give you just a little break from the pain and release healthy, healing chemicals into your body.
Use your own personal spirituality to explore what death or loss means to you and your spiritual self. Write down the things you have learnt - what have you noticed about yourself in this time? What have you found hardest? How did you over-come the hard things? What did you find easiest? What does this tell you about yourself? What have you learnt about your life? What beliefs have you gained, let go of, or are new to you? How might you use this knowledge in your future?
Lastly, be kind to yourself. Time heals wounds. Sending healing thoughts your way.