Status showing failed state

Hello All,
I was making changes in grafana.ini files for github authentication and it worked and after that few more modifications and multiple times stop and start of the server.
No my server is not starting, even if I replace original grafana.ini as I kept backup before making any changes.

command I am running to check status " service grafana-server status" and it is showing
● grafana-server.service - Grafana instance
Loaded: loaded (/usr/lib/systemd/system/grafana-server.service; enabled; vendor preset: disabled)
Active: failed (Result: start-limit) since Thu 2018-07-12 00:05:13 IST; 20min ago
Docs: http://docs.grafana.org
Process: 30168 ExecStart=/usr/sbin/grafana-server --config={CONF_FILE} --pidfile={PID_FILE_DIR}/grafana-server.pid cfg:default.paths.logs={LOG_DIR} cfg:default.paths.data={DATA_DIR} cfg:default.paths.plugins=${PLUGINS_DIR} (code=exited, status=1/FAILURE)
Main PID: 30168 (code=exited, status=1/FAILURE)

Jul 12 00:05:13 inmyzcg0038 systemd[1]: Unit grafana-server.service entered failed state.
Jul 12 00:05:13 inmyzcg0038 systemd[1]: grafana-server.service failed.
Jul 12 00:05:13 inmyzcg0038 systemd[1]: grafana-server.service holdoff time over, scheduling restart.
Jul 12 00:05:13 inmyzcg0038 systemd[1]: start request repeated too quickly for grafana-server.service
Jul 12 00:05:13 inmyzcg0038 systemd[1]: Failed to start Grafana instance.
Jul 12 00:05:13 inmyzcg0038 systemd[1]: Unit grafana-server.service entered failed state.
Jul 12 00:05:13 inmyzcg0038 systemd[1]: grafana-server.service failed.

Please help, I have already tried , stop start and reload all that but still same error messages in status.

check grafana-server log (/var/lib/grafana/grafana.log)