Have you tried relaxation exercises? Yoga and Meditation has helped millions. Its helped me. I used to have a tree full of screeching monkeys jumping up and down in my head and that other voice putting me down. 8 months of sobriety and 6 months of meditation sitting quietly focusing on my breath for 20 minutes every day and the monkeys are mostly quiet and the voice has completely gone. Therapist told me to take it up, its called mindfulness meditation. Try it. You'll struggle to focus for 10 seconds at first but with practice you will quiet your mind and get this inner peace.