Went to optometrist and was told I have slight edema in my right eye along with a small fold in cornea and worse astigmatism. Heal in time? 2nd opin.?

Keratoconus? Given your age and description, you probably have keratoconus (a congenital weakening of your cornea). Go see a cornea specialist immediately and ask about collagen cross linking. It may save you surgery down the road.
Unusual at age 20. There are a number of possibilities but nothing likely to be serious at your age. Optometrists frequently are at loss for words when they detect things in eyes and it is best if you need anything other than eyeglasses or contacts, to see an ophthalmologist which i suggest you do for these findings.