From Longman Dictionary of Contemporary Englishunburden yourself (to somebody)unburden yourself (to somebody)TELL A SECRETto tell someone your problems, secrets etc so that you feel better → unburden
Examples from the Corpus
unburden yourself (to somebody)• George dropped his hands from his face, and very quickly realized that the young man was longing to unburden himself.• He had been feeling guilty and needed to unburden himself.• The laibon now begins to unburden himself.• Nevertheless, I feel the need to unburden myself in print.• To unburden themselves of arranging and directing these tasks, grieving families turn to funeral directors.• It was as if Jack was preparing to unburden himself, to share his secrets with her.• Sometimes he would have liked to unburden himself to somebody, but his officers and men had their own problems. 