Hello, I'd like to help you with your question.
Yes, it can be cured with therapy and self help. If you have been cleared by your doctor for the hypersensitivity not being based on a medical issue, then it can be assumed the symptoms you are having are emotional in origin. In that case, then therapy and self help are the next treatments you should try.
Hypersensitivity to noise may be attributed to disorders such as Autism
or fears/phobias. If you suffer from a dislike of crowds, that could also be part of a fear or phobia. In that case, you have an excellent chance of greatly reducing your symptoms or even eliminating them. Therapy and self help are the best options for treatment for a dislike of crowds. You can learn to socialize in small steps so you can adjust at your own pace to integrating into social groups. The hypersensitivity can also be coped with in steps. By exposing yourself slowly to more and more noise, you can grow used to the increased noise.
The first step is have an evaluation by a qualified therapist to get a diagnosis. Once you know what you may be dealing with, the therapist can help you find the right treatment. You can try individual therapy, group therapy and/or mediations depending on your situation and diagnosis. Self help is another option. If you have a diagnosis, you can find books and other resources which can give you options on how to address what you are coping with. With the combination of therapies, you can feel better soon.
I hope this has helped you,