what to do for making someone used to love me to love me again ?

there is a guy who liked me and i wasn't feeling anything for him ... he thought that i am his grilfriend and when we talked i kinds broke up because he was acting really wierd ... and now i want him to love me i feel that he was good for me and i am so stupied that i lost him .. tell me what to tell him in a nice text ... like some nice words ..