Any book suggestions to overcome shame, insecurity and feeling of inadequacy when trying to achieve a goal (think academic)?

I am preparing for an entrance exam. I have failed 6 times now. My mind is my biggest enemy. I am in therapy. I have suffered years of bullying for being gay. I had developed a coping mechanism of being a perfectionist to get by. But that has severely impact my self esteem when I’m not the best. I know I can’t be the youngest, best and greatest at everything always. I’ve recently accepted that. But I still struggle with feelings of shame and imposter syndrome when I don’t meet my goals.