Yes, a yeast infection does go away on its own. The cream you can get to treat it helps with the itchiness. I used to get yeast infections ALL the time, but now rarely get them. I do remember how uncomfortable they are though. Good luck!
I've had several yeast infections that went away and then I've had some that did not. I think sometimes it can depend on just how bad the infection is. VagiGuard is a great anti itch cream that I've tried and its only about $7 but is ONLY anti-itch. You can try Monistat if you want OTC or if you talk to your doctor they can give you Diflucan which is WONDERFUL.
If you are wanting to avoid the doctor then try talking to the pharmacist at any drugstore and they can give you input on which creams are the best. Eat yogurt and I've also heard that garlic helps kill yeast. Good luck!