I ended up downloading the blockchain from https://consensus.siahub.info ... It took around 12 hours to catch up the consensus (upon download, it's around 7 hour old).
Then errors appeared in transactionpool.log. So I removed the directory and let it regenerate everything. I did not know how it take but after I wake up, everything was up and running.
I checked host.log and found lots of error too. But it repaired itself... Perhaps the transaction pool could do so too.
Help