help...

oh how my heart aches as I type this... I found out my boyfriend, my world, cheated on me for weeks as I laid by him every fight reminding him of how much I loved and adored him with every ounce of my heart. I ache, I hurt, I’m angry. I don’t understand why I wasn’t enough. I don’t understand how he walked away so easily. I don’t understand why I’m the only one hurting. His response was this is “karma”. I’m so... baffled... confused.... but mainly tired and drained. My heart is crushed and I can’t do anything about it. Help