Someone i loved betrayed me, how do i overcome this?

i loved someone who said they would love me forever. i broke it off with them because of something that had nothing to do with them i was trying to please others but i had to do it (sorry for not whole explanation). and so while i was broken up with them i always talked to them and whenever they needed me i was there. i PRETENDED i liked someone n they got cut at me for it. but ye i told them i was joking. anyway a week or two later i realise i had a made a mistake n who cares if ppl dont accept us, so i invited them over n ye well i umed we were bak 2gthr. then they tlkd to me after they left n said it was a mistake n that they had feelings for someone else. this was only a week after i pretended the exact same situation, except they werent joking! i went 4 2nd best, firneds n they betrayed me.. they treated me like an absolute idiot on the net and infront of there friends. bt whn we were on foen or alone it was different. its alot more indepth but ye. how do i overcome this feelin