Grafana has become very slow with time

Grafana version : 5.4.3
DB : Postgres

My grafana has become very slow. I understand that part of it could be related to the backend database but still just the listing of dashboards takes hell lot of time in Home Page.

Loading of dashboards taken long long time ( May depend on DB as well )
Loading of home page also taken lot of time around 20-30 sec apprx.

This mainly happens when multiple users are logged in. Is there any setting to enable multiple users ?