I would recommend you get rid of it from the root cause which is your diet. Cut out sugar and clean carbs like pasta and bread for a month and see the difference, you'd be surprised. Also washing your face with products that have salicylic acid extracts and scrubbing twice a day as well as using sunscreen regularly should definitely improve your overall facial appearance if done consistently for at least a month. As for the back and shoulder acne I would recommend you take frequent showers and scrub your back and shoulders but not too hard cause it might just make things worse. If you want to visit a dermatologist you can go to "Rank dermatology clinic" I know a branch at 'wolo sefer'. You might have to bring 1500 birr with you and it should be more than enough to cover all your expenses, including the purchases of the medications they will prescribe for you.