Hi Katie. Your post made me laugh as it all sounds very dramatic!!
The success of the peel will be down to two main factors. 1) The skill of the operator - Using the correct strength of product, checking your skins reaction before and during treatment, assessing your skins thickness, asking you questions that will inhibit or enhance results ie, do you smoke, do you sunbathe, what you use on your skin etc 2) The extent and depth of scarring. This depends on your age, the type of acne you had (was it cystic acne?) if you have pits in the skin, if you have severe collagen and elastin degeneration around the area.
So you see there can be many variables as to succes.
However, generally, you will see between 20 - 30% improvement in your skin. You will look rather awful after a few days but as long as you don't pick or pull off the dead skin flakes (very, very important) your skin will look fantastic. You will never be able to expose your face to the sun again though and will have to wear a good quality block everyday. If you don't you may get a hyper pigmentation on some area of your face, which will be permenant and will not look nice.
Please make sure that the dr performing the treatment is a suitably qualified dermatologist and (more importantly/assuming that he/she is) that he/she has carried out many of these procedures previously.
Make a list of questions you want to ask and if you don't understand the answers fully, then ask again. Ask for portfolios of other customers - before and after pics.
Good luck.