All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
May Allaah enable you and us to do good deeds. Know, that these thoughts are nothing but whispers from the devil in his attempt to prevent you from performing good actions and drive you away from the circles of knowledge and from praying in congregation. Imaam Ahmad reported that a man came to the Prophet and told him: "O Prophet of Allaah! I find in my own self desires which I prefer to die rather than talk about (consider as a great and serious matter to talk about). Thereupon, the Prophet said: "Allaahu Akbar, Allaahu Akbar, Praise be to Allaah Who has turned Satan's cunning into mere insinuations and whispers." [Ahmad]. Hence, these whispers are from the devil; so do not take them into consideration. What would help you to repel these whispers is to seek refuge in Allaah from them, Allaah says (which means): {And if an evil whisper from Shaitân (Satan) tries to turn you away (O Muhammad ) (from doing good,), then seek refuge in Allaah. Indeed, He is the All-Hearer, the All-Knower.}[Qur'an 41:36]. Besides, you should avoid thinking about them. You are forbidden to abandon congregational prayers on the grounds that you fear showing off. Congregational prayers are an obligation; this is explained in Fatwa: 82538. Indeed, the scholars stated that abandoning a good act of worship on the basis that people might say that one is showing off, is indeed showing off. Al-Fudhayl Ibn 'Iyaad said: 'Abandoning the performance of a permissible act because of people is showing off, and performing a permissible act for people's sake is Shirk (associating partners with Allaah), and sincerity is to be saved by Allaah from these two thoughts.' Furthermore, you should not have abandoned making the call to the prayer, as this is one of the most important acts of worship. If you open the door for these whispers, abandoning the performance of acts of worship, then you would have abandoned all the obligations and, thereupon, committed great major sins, and this is the objective of the devil. Therefore, you have to seek Allaah's Help and continue performing what you have been doing, like praying in congregation in the mosque, making the call for the prayer, attending circles of knowledge, and you will be fine, Inshaa' Allaah. Try to repel these whispers when they come to your mind, and supplicate Allaah as much as possible and read the Qur'an. By doing this, you will succeed in repelling these whispers, Inshaa' Allaah.
Allaah knows best.