I bought some bitcoin in March 2017, sell half of it in Dec 2017 and hodl the other half since then. The current downward trend seem to last for a very long time and I'm quite upset about it. What do you guys think? Should I hodl or sell all my BTC now?
Patience is a virtue bro.

if you can still afford to hodl it and don't need the money yet. I would suggest thay you hodl it. It's pretty hard to tell if bitcoin would recover to the point where you'll earn or even have your investment back, but atleast bitcoin has been having good news right now. Maybe it could affect the future prices.