I've never noticed you post anything that suggests your brain malfunctions. You seem to be a coherent person who is able to study college level academics, hold a job, and enjoy many interests including music. You've been proactive about your own growth by seeing a therapist and more recently, by arranging TMS. You have friends, and your sisters-in-law are being supportive by wanting to help you feel more confident.
Head-hitting is a fairly common BFRB for autistic people. It doesn't mean that your brain malfunctions! The reason you feel so different to your peers is that you are living in an area where most people have significantly different values or goals. I sincerely wish you could find a way to relocate so that you don't feel trapped and alienated by your environment. Have you ever sought help from a caseworker or therapist about how to move away from your location? It's just a thought, but I believe it would really help you to feel more hopeful overall.
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And in the end, the love you take is equal to the love you make.