Boday aches and long term bruise. I do?

From your question it appears you wish to know two things. One, what to do for bruise and second is about body aches. You have not mentioned what caused a bruise on the back in first place, it would have helped. Smoking affects your body's metabolism and immunity. So on one hand, the healing of wounds is delayed, on the other hand smoking decreases appetite. I understand its very cliche for a doctor to advise you not to smoke and that its easier said than done. But consider this an opportunity to begin to gradually quit smoking. You may consider reducing the number of smokes per day gradually and trying nicotine gums if it helps. Try and eat regular meals and at least 5 servings of fruits n veggies. Keep yourself hydrated. Avoid too much coffee, tea n soda.  Your health is in your hands. If you were concerned enough to post this query, you must care about your health. All the best!

If the bruise doesnt heal in next few weeks, consider making a physician appointment to get examined.