Thanks for your query
You stop using razor blade because it inflicts microcuts which later on get infected and cause severe itching
. At present you can opt for trimming and later on when the skin is completely healthy , you can use creams. Also take special care of hygiene of that area. Use good antibacterial soap.If the problem does not subside, you may need some antibacterial creams and antibiotics. It will help you.
Best of luck and take care...
Hope it helps you..