In all honesty, the only line I really liked was "Your loyalty was no longer to me." The rest seemed really cliche. However, I do not feel that this is a topic that should be completely disregarded. Adding aspects such as imagery, metaphors, and establishing a consistent tone will bring much improvement to the piece.
This was all tell and no show, and loses all structure halfway through - the last five lines seem more like prose than an actual poem. Find an original way to convey this story, using metaphors, similes, imagery...anything to make it your own. Good luck.
I love her dearly, but I can’t live with her for a day without feeling my whole life is wasting away. — Miss Kenton, The Remains of the Day by Kazuo Ishiguro