Fix Is the server running on host "localhost" (::1) and accepting TCP/IP connections on port 5432?
Most likely it's because your system shutdown unexpectedly Try
postgres -D /usr/local/var/postgres
You might see
FATAL: lock file "postmaster.pid" already exists HINT: Is another postmaster (PID 449) running in data directory "/usr/local/var/postgres"?
kill -9 PID
kill -9 419
And it should start postgres normally