Hi, may I know what happened to my 2 months old.

Looks like diaper rash. You can try Desitin (purple) for fast relief. Desitin (blue) for daily use. Sudocrem also works well. Find a brand that has zinc oxide ingredient in it. The higher the better. And also, don’t wait too long to change diapers. Once poop, change immediately. Change before or after a feeding session. For girls, it’s crucial to wipe from top to bottom to avoid bacterial infection. And wash whenever you can. Can consider a watering bottle in your diaper changing area.