Ok lets see. You say that your fusion and store gel causes you irritation, well a single blade DE or straight will probably cause less once you can use them. I dont expect it will be a cure for acne directly, but you will be using better products on your skin and these may prove beneficial. The DE is going to be the cheaper and easier of the two options so have a look round, you will also need some PROPER soap and a brush but these dont have to be expensive - just good. With a straight you'll be needing a strop and a hone of sorts as well and learning the straight is a bit harder. Sorry Im not trying to put you off but the DE might prove to be the quickest way to get away from the demon fusion.
Good luck