You might find that after a shower blow drying that area with your hair dryer on low might help....instead of using a rough towel. Also, when you wee, don't wipe but kinda blot...does that make sense? If you clean the area fanatically then your skin might lose some of its natural oils, making it more itchy etc.
Don't be embarrassed if it's thrush...I had it once and just went to the chemist and picked out a female worker who was helpful....
Also, I use those Kleenex toilet tissues for #2's....keeping that area nice and clean....and it's a nice psychological thing too!