Satan has strange ways to prevent people from doing good deeds. One of them is to convince them that they are not doing what they are doing for the sake of Allah. Through his whispers, he tells you not to pray or not to give money in charity because someone is looking and you may not be sincere in your actions. Those who listen to his advice and obey him end up with OCD and would always doubt everything they do. He would literally destroy people’s lives through these whispers of his. You should ignore these whispers and increase what you are doing so that you would harm Satan by doing that. It was reported that a man was walking with his friend when they say a funeral going to the graveyard. One of them said to the other: let us follow it. The other man paused for few seconds and then accompanied his friend. He asked him: why did you pause? He told him that he wanted to follow it because his friend told him so. That is why he paused to make his intention solely for the sake of Allah.
Therefore, the one who is advising you and telling you that you are showing off is Satan himself. Ignore him and intend all of your actions for the sake of Allah.