Zenfone C laggy after hard reset

Hello!

Recently, I performed hard reset on my ZenFone C, wished of cleaning it thoroughly.
But when its done already, i experience a more laggy phone and it perfomes slower compare to the days i first have it.
my thought of polishing it to be more faster returns to be more laggy, slower and a bit annoying. I can`t even open two apps at a time.
I`m worried and really asking for solutions and things to do to improve it a run it like it was used to be.
Thank you and hoping to receive some helpful insights.