"These regrets lay quietly, Deep within my mind,"
`I dont think deep needs to be capitolized. I dont see any reason for it to be. This line is simple yet says so much.. those regrets kind of sink down deep within your mind.. simply written, understandable. Good job.

"Day by day decaying, Until I come to find,"
`Oh, perfect! Decaying is a powerful word.. I'm glad to see you used it here.. it's the perfect description. Regrets and decaying go very well together. Uncaptiolize until.. not quite sure why you have it capitolized.

"Their purpose I know not of, Their motive I'm not sure,"
`This is amazing! Kind of makes me wonder why you are actually having these regrets. Dont capitolize the word after the comma, thats not needed.

"But as they lay there resting, My mind is never pure."
`Oooh, love the word pure. Kind of like.. as these regrets are swirling throughout your mind, you are probably confused, nothing is clear in other words. Simply written, I love how such simply written lines can hold so much meaning.

"One day they'll attack, After many dormant years,"
`I love how regrets seems like a person or thing.. the word attack is so powerful here. Dormant, great word as well.

"Recalling me way back, To the terror and the tears,"
`The regrets will make you think of the past in other words.. and all you went through. Greatly said.

"These regrets are aching, Aching to put things right. "
`I think this would sound better..
"These regrets are aching, aching to make things right."

Overall, well done. Simply written poem.
But I enjoyed it overall, the only thing was
how you capitolized the word after each comma, that was not necessary. Otherwise, good job.

5/5.

I can feel the emotion in every line and they all blend so well