What does griefs of mine own lie heavy in my breast mean?

The phrase "griefs of mine own lie heavy in my breast" conveys a deep, personal sorrow that weighs heavily on the speaker's heart. It suggests that the speaker is burdened by their own emotional pain or experiences of loss, which they may feel are difficult to express or share with others. This internal struggle indicates a profound sense of isolation and the weight of unresolved feelings. Overall, it reflects the complexity of human emotions and the impact of grief on one's psyche.