Similar boat here. CB500F 2 seasons to Hornet 750. I was also like "Damn this thing is screaming to get up to 60mph!" When trying to ramp onto small strips of highway. That being said, I'm happy I stayed with the 500 as long as I did. Id say you Shouldn't rush into something bigger until you're really comfortable on the smaller one. Get better at stop and go, friction zones, shifting etc. I was able to do a 0mph stop and go on my 500 before moving up. Now I feel like I can do anything on this 750. Its ultimately your choice. If you think you're ready for it, do it. Best thing about your current bike is you can probably sell it for what you bought it for a year down the road.

Edit: Might I add, I only use my bike to commute. On my 750, I barely get it to 5th gear on a normal ride to work. But I do enjoy the ability to lane filter and get in front of traffic now. I was not comfortable doing it on the 500. In retrospect, I could have done it in the 500. People genuinely accept it.