OMG hugs to you!
I know all about this horrible condition, I had it in 2005 and I was stuck with it for 5 months until I was (finally) put on the right treatment, and I also had a breakout of it this year but it only lasted a couple of weeks.
You need to go to a dermatologist, not a doctor.
GP's seem to want to treat any rash with steroids (I was sent to about 4 doctors, all gave me steroids, all made it worse).
The proper treatment for perioral dermatitis is usually tetracycline or similar. Your dermatologist might want to try topical antibiotics before tablets, but topical creams tend to be less effective than actually taking antibiotics.
Lifestyle factors can play a role too. My dermatologist told me to stop using fluoride toothpaste (I now use herbal toothpaste that doesn't contain any fluoride). It's important to avoid getting any chemicals or creams on the affected area - whatever you do do NOT try and cover it up with make-up, it makes the rash so much worse.
Also, avoid any foaming facial cleansers. My dermatologist told me to not even clean the area with anything but luke warm water - cleansers, make-up and even hot water can make the rash worse. I now use cetaphil gentle skin cleanser, which has no sodium lauryl sulphate (a chemical ingredient which makes stuff 'foam up').
Are you going through or have you recently been through a really stressful time? Stress is what made it break out on me. It sounds silly, but Perioral dermatitis is often a result of being really stressed and run down (as well as a combination of other factors), because stress changes lots of hormone levels in your body and hormones often play a big role in developing perioral dermatitis, so if you are really stressed you should try and take lots of time out.
I know how horrible this illness is. It's really frustrating and makes you very very emotional and depressed. I'd really recommend going to a dermatologist and pushing the strong oral antibiotics treatment. It WILL go away with time and with the right treatment, I promise, and one day it will all be a nasty memory. Best of luck to you!!!