When will the bull run start?

in 2018? i've lose a lot of money through bitcoin. because price went down. when will the bull run start and i regain my money?
It will start when it wants to. Price going down now does not mean it would be like this forever. Trends change and there will always be a time for both bears and bulls to do their thing which for this year, the bears are hugely smiling.
If you understood the volatility before investing, by now you should not be bothered, unless of course you invested more than what you could afford to see go down hugely in the short term.
Just take a chill pill and know that no matter what, the market will at one point recover and what you should be targeting now is buying more at dips.