how should I unmask my 'class clown' behaviour and make people around me to respect me.

I'm at some point of realisation now, I feel like this behaviour have always did me bad rather than good.I have always been lonely and shy so I adopted this in my first year of university to socialize with others and make new friends. It did work though, I have many connections now and I don't feel much lonely but still i don't get the respect that I crave for. sometimes I feel people around me don't take me seriously when I try act mature and be serious and people often take me for granted.I feel like i have to change this behaviour but I don't know how. I was going through some issues this week so I stumbled on self love and self-respect by chance and realised how I have been neglecting myself and how it deteriorated my self esteem over the years..Also I'm grateful that I realised this soon and I will also suggest others to not ignore these issues.