There are many regrets which Othello expresses at the end of Othello. He has made many mistakes and errors of judgment, not the least of which is his misplaced trust in "honest,honest" Iago. Now that he has realised how manipulated he was by Iago and how he has committed heinous deeds, although "nought I did in hate, but all in honor," he is preparing himself to die- as an honorable man would do.
There is a wistful albeit remorseful, tone to Othello's "farewell" soliloquy as he compares his deeds and his losses. Othello wishes he had not been so "unlucky" and his most earnest wish is that he had not been so overcome with rage, once his jealousy was aroused. He claims that usually he is not a jealous man and unfortunately he was unable to control himself once " wrought."
Othello acknowledges that he "loved not wisely but too well" indicating that he put everything into his relationship but was misguided by occurrences (and Iago of course). He states that his life has been one of service to the state and hopes that that will be some small redeeming feature and will be recognized and acknowledged after he has gone. He would not like to be remembered only as "malignant" and in taking his own life he is effectively helping society rid itself of this "turban'dTurk."
Speaking of himself in the third person also adds an element to this dialogue as perhaps he retains some measure of his reputation,having discarded all that was good in his life - " a pearl .." - he can still be of some service to his beloved adopted country.