actually she is the loser not you, because she left a guy who was really in love with her. her current boyfriend may just be using her for fun and she will realize it sooner or later.

there are so many nice and honest girls out there and you deserve one for sure. next, you need to live not just for you, but for your parents, siblings, friends, etc. can you imagine how bad your parents or your friends feel if they lose their hardworking and honest son or friend like you? be strong man, this is just a small loss, i would say an important gain for you eventually because you lost an dishonest person who would run behind money and could betray you at any time in the future even if she was with you now.