I've had the same issue. I would advise you to see a proctologist, not just a regular doctor.
A proctologist has experience with the butt problems, so the issue of embarasement should not be there.
He'll make you feel comfortable to talk about it and comfortable during the exam.
The issue of being dirty and itchy even after you clean up is because your internal hemorrhoid veins swell up and your butthole will not hold the fluids inside properly. The mucus and feceis will leak out and irritate the nerve endings. It's why you feel itchy. So the solution is to prevent your hemorrhoid veins from swelling up.
You should make sure that you clean up yourself a few times a day, maybe take a quick shower if possible.
DO NOT USE TOILET PAPER! Use medicated wipes, get them at your local pharmacy. Drink plenty of fluid and take some fiber. Try Calmovil, it's a herbal remedy that helped me, see it here: Calmovil Hemorrhoid Treatment
Do the above and you'll feel better fast!