I don't know why it hasn't worked, but as you've given it a year, go back to the doctor and ask for something else as this clearly doesn't work for you. (I have found that my doctor has little clue about such things, just says your skin looks ok now. Well it would the amount of make-up I have on to cover it!).
Seriously though, there are lots of treatments and due to their nature not all of them work for everyone, but I'm sure there is one that will work. Make sure your doctor realises how bad it makes you feel, often people who have ok skin themselves do not realise.
Try and think if it gets worse at certain times, like time of the month, when you're hot/stressed/tired etc, after you've eaten certain foods etc. to try and give them as much info as possible. If they have good skin and haven't dealt with a lot of skin complaints, they need pushing in the right direction. Be assertive.
Good luck (I'm having to wait until my face goes bad again, to then try and get an appointment, so they'll prescribe me something new. Oh joy..).