I need some advice.

I’ve been talking to this guy since September 2019 and we’re supposed to be in a relationship but I personally don’t feel like I’m ready for a relationship, but I dunno how I should tell him because I really REALLY don’t want to upset him , I know this makes me sound like a bit of a player but I’m not sure what I should do 🤷🏻‍♀️ please someone help.