Is what our master Uthman, may Allah be pleased with him, did when he reminded people of his virtues and deeds considered a form of the forbidden boasting [minn] in Islam, or is a person allowed to mention his good deeds if people's ingratitude and denial increase?

The scholars mentioned that the Companions are to be thought of with the best assumptions, and their actions are to be interpreted in the best light. Uthman, may Allah be pleased with him, is the best of the Companions after Abu Bakr and Umar. A person is forbidden from mentioning their good deeds for pride and admiration. However, it is permissible to do so out of necessity, such as repelling evil or achieving a benefit for people. Uthman's informing others of his deeds falls under this category. Likewise, it is permissible for you to inform others of good deeds so that you may be emulated, or to achieve a benefit for Muslims. As for informing others for the purpose of showing favor to the recipient of one's benevolence, it is forbidden by Sharia, due to the Almighty's saying: "O you who have believed, do not invalidate your charities with reminders [of it] or [other] injury" (Quran 2:264).