First girlfriend, first breakup

Hi im new in this group and I have some words i would like to say. I was in a long-distance relationship for a little over 3 years with a girl from Mexico and im from Denmark. We met "only" twice (3 months in person total) and I was the one who flew 10000+ kilometres for her and worked close to 50 hours a week plus school while she didn't contribute anything that would make us be together. How does someone like me who put this girl first for 3 years and got the best relations with her whole family and even some friends. It all ended about 2 months ago after a very very tiny argument and she texted me "I am not ready for a relationship" I have never felt more betrayed or worthless after that. Any tips?