How can the one who gives charity avoid showing off and ensure the acceptance of his good deed, especially after his initiative has become known and he is no longer anonymous?

May Allah reward you for your eagerness to do good. Announcing good deeds is better than concealing them, due to the benefits that accrue from them, people's participation in them, and the aid provided to those in need. Be keen on sincerity and negate the impurities of showing off by remembering Allah Almighty's awareness of you, and that He is the rewarder for this action, and that you seek no reward or praise from anyone, but rather you seek Allah's countenance through your work. Supplicate to Allah to grant you sincerity and protect you from showing off. However, beware of abandoning good deeds for fear of showing off. Rather, exert effort in doing good and strive to attain sincerity, holding a good opinion of Allah Almighty, knowing that He alone is the one whose praise benefits and whose censure harms.