Don't worry you don't have to live with acne, Benzoyl Peroxide is only one of the many treatments available. Retin-A is a synthetic topical retinoid which is very effective but should not be used at the same time as another acne treatment. If you use Retin-A again rebalance your skin with bland cleansers and moisturisers such as those by La Roche-Posay. If Retin-A is too harsh try Differin (adapalene 0.1%) a different topical retinoid which is generally well tolerated. Avoid Duac gel since this contains Benzoyl Peroxide and Clindamycin, but consider Dalacin which only contains Clindamycin.
Alternatively you could use oral treatments instead of topical ones. A course of oral antibiotics such as Lymecycline or Oxytetracycline will clear acne. Also consider switching to a combined birth control pill (Diane35/Yasmin/Ortho Tri-Cyclen etc) as oestrogen blocks the actions of androgens- the hormones responsible for stimulating oil glands in the skin. Avoid the mini-pill, depot shot and hormonal IUD as these can induce acne.
I have replied to a few other posts because I want to share what helped me with my mild acne. Maybe you really need professional treatment for your acne, but if you want to try something mild in the mean time, I would recommend Clinique's 'anti-blemish solutions', especially since your skin seems to be extremely sensitive. Clinique is know for being created for people with allergies.
I'm 25 years old and I used to suffer from the same problem as you ever since puberty. My skin was either too oily or overly dry, so I kept drying out my skin with different anti-acne products and ending up with oily skind and break-outs all the time, despite moisturising. I always envied those friends who seemed to have flawless skin, while I kept breaking out like a teenager...
Despite having been on birt-control for several years I kept having break-outs. I tried and endless amount of different products, cheap and expensive ones, anti-acne treatment and so on. About 6 months ago I found 'Clinique anti-blemish solutions' and it totally changed my skin! It's rather expensive but worth every penny. It's a cleansing foam, tonic and moisturiser that you use every morning & night. I was sceptical at first because usually I would break out even more when I used moisturiser at night. About 3 weeks after I started using it my skin changed. Now I rarely have any spots and my skin is neither oily nor dry, I only occasionally get a few spots when I have my period. So despite sounding like a commercial for Clinique: try it! I hope it will work for you too. Good luck! :)