anybody know how to help her ?

So yesterday my little girls privates started getting red so we put Desitin on her and we changed her diaper throughout the night. When we got up this morning I went to change her diaper and seen this its right on the outside of the crease from her leg. We then put anti fungal cream on it but it didn't seem to help much all it did was make it blister even more. I feel so bad for her because she screams everytime we try to change her.