I hate emotions

He has me all sorts of confused.. he said he wants to date and I'm his, first couple of days treated me like a princess, then he kinda got dry and told me that his definition of dating was he got to date other girls st the same time .. he says me and him don't even have titles as in boyfriend and girlfriend but everytime I bring up how upset it makes me he says he's gonna dump me... how can you dump me if we aren't apparently even a thing?! I swear I've never stressed so much over a guy and I shouldn't be, being older makes you want something serious 100xs more.. just be honest and stop wasting my time.. tell me if this is worth or not . This guy has me so emotionally unstable ...