Here you have told you have symptoms like heart burn, heaviness in eye,
back pain and weakness.
This all symptoms could be related to withdrawal effect of smoking, gastric problem may be
gastritis and acidity, low body immunity,
vitamin b deficiency, spinal
muscle weakness.
You have also mention you take some medication. But your explanation is not clear which medication it is and for what it is, as well you have not inform about your previous medical history so specific guidline is not possible but can suggest in general as bellow.
First you consult a doctor and do your
blood test for
complete blood count, vitamin b, calcium check. Then also go for ECG. Now based on report if any thing gets detected follow treatment. If all reports are normal then you need to visit a gastro entrologist because it can be related to gastritis. And let him examin. Again as per his evaluation follow treatment. Now if that is also normal then visit a ortho and get your self examine for back pain and take treatment as per his advice.
Here for normal back pain I suggest
physiotherapy is a good option of treatment.
In last I suggest you to change your life style and food habits. Do not eat spicy food. Maintain your food timing. Have good break fast, average lunch and minimum dinner possibly at or before 8:00pm.
At the same time do regular walking or cycling exercises. Take appropriate sleep. And keep positive attitude.
You can also use hot and cold pack for your back pain for some more relief.
So this are the in general suggestion from my end. Since there is no proper information available clear diagnosis is not possible.
Take care.