My only regret in life is not expressing my appreciation for someone I loved so dearly

My only regret in life is not expressing my appreciation for someone I loved so dearly. Stupid because that was a reason why he broke up with me, and it still haunts me till this day. I guess it wasn't that I didn't notice the things that he did, it was just that I was scared that he would get tired of me expressing my gratefulness. What a stupid fear, what an absolutely horrid excuse. It has haunted me for so long and I don't know if I can ever recover from the guilt that I feel.