Hi. Thanks for your query. Read and understood your history. It looks that the recurrent touching or cleaning the area habitually over a grown part of the nostril has caused the thinning, soreness of the skin and I would suggest you the following: First of all stop touching this part of the nose consciously. This alone will allow it to recover over the weeks. If there is soreness you can apply oil-based antibiotic ointments to avoid the infection, the sore and allow the area to heal well. The cartilage must have been over the years and if required can be corrected by Surgery. Consult an ENT Surgeon to get a clinical evaluation, examination and further advise for you to get cured of the problems permanently.