Hello sir, sorry to read about your troubles!
When there has been an irritation, it is a little more difficult to get rid of it. The second option you were advised, moisturizing, is in my opinion the best way to go. It doesn't have to be this cream, it can be any other fragrance-free product like Cerave, Cutibase, Aveeno, Vaseline cream, etc.
I suggest applying them at least 3 times a day on the irritated area.
I also suggest, if you haven't already done so, to use a fragrance-free soap, such as Dove bars (those that specifically mention fragrance-free) when showering or cleaning. You should avoid using water that is too hot because it can dry out the skin, and avoid rubbing too vigorously when drying. Ideally, you should lightly pat the skin to leave a very thin layer of moisture, then apply the moisturizer afterwards.
Finally, if possible, I suggest trying not to exert too much force when masturbating, and using a personal lubricant when doing so, such as K-Y or similar. This may help reduce friction and irritation.
I hope this was helpful, and if you have any other questions, please don't hesitate to ask!
Tom Samaha, Pharmacist