You wrote "you'll never hear from me again" as a kind of way to trigger a response from him. You're hoping for that, you have feelings, which is fine.
Threatening a guy into relationship is just so immature and just terrible. Wouldn't you want to be with someone who truly cares for you, would never use you, and would support you in every difficult situation you may have in life? Why would you want to humiliate yourself that way JUST to get a boyfriend? it's not worth it
Just cut it out, don't message him again, refrain from meeting him in person, forget about it, and take a lesson out of it: just because a guy wants to sleep with you, it does NOT mean he has any feelings for you, it does not mean something serious could come out of it.
Be careful, take care, and don't do stupid things