私は、この事を言ってしまった事が悔やまれる。

I; me; private affairs; personal matter; secrecy; selfishness

topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis

this (something or someone close to the speaker (including the speaker), or ideas expressed by the speaker)

thing; matter; incident; occurrence; event; something serious; trouble; crisis; circumstances; situation; state of affairs; work; business; affair; after an inflectable word, creates a noun phrase indicating something the speaker does not feel close to; nominalizing suffix; pretending to ...; playing make-believe ...; alias; aka; nickname; alternative name; also known as

indicates direct object of action; indicates subject of causative expression; indicates an area traversed; indicates time (period) over which action takes place; indicates point of departure or separation of action; indicates object of desire, like, hate, etc.

to say; to utter; to declare; to name; to call; to go (e.g. "the alarm went ping"); to make a noise

indicates sentence subject (occasionally object); indicates possessive (esp. in literary expressions); but; however; still; and

to mourn; to lament; to be sorry; to regret; to repent