How can one strengthen their trust in religion and in themselves, and overcome feelings of inadequacy, in light of doubts about religion and excessive sensitivity towards people?

Fleeting emotions such as feelings of inadequacy or a lack of self-confidence do not affect one's faith. Allah has overlooked the thoughts of the soul unless they are acted upon or spoken. These emotions are natural in youth and will diminish with age and experience. To boost self-confidence: set your goals and plan for them, read the biographies of imams and scholars, focus on your positive aspects, strengthen your love for and attachment to Allah, and attend courses to enhance your psychological well-being and communication skills.