It's sad to be addicted to such life threatening substances, I guess the best way to get out of it is to get rid of the cause for which you took drugs like get cure of depression, or sadness etc. Taking drugs for a long time can just shorten your life span. You can quit cold turkey which might not be fruitful since you would be back to it, so see a doctor and gradually reduce the dose!
Doctors are the one made drugs as one of the successful business in the oast few decades, most of the medicines we are intaking has side effects so these medicines are created with the purpose of making people sick always so they will take medicine for time to time.We should change our life style to make effective change but as it has been said it is going to be a tough journey.