Someone help me im young and dont know this emotion yet?

think guy i like is dating this girl and me and him have dated before but we broke up and i still have feelings for him and he told me he still feels the same but the other day i found out he broke up with his gf and i got my hopes up and thought he was gunna ask me out but then he asked someone else out and when i found this out my stomach dropped and my throught closed up and my chest hurt and i could not breath what is this feeling heartbreak, love, betrayal, what is it