Hello.
Thank you for your query at DoctorSpring.com.

I have gone through your history in detail. It seems that your GERD is not very well controlled.
Let me answer each of questions individually.

1. Should I go for endoscopy or will it cause any further damage as I have seen in many cases if the instruments are not properly cleaned then It can cause further complications.
I would also suggest that you undergo endoscopy. This is actually a very safe procedure without any major complications and in established health centers, sterility and hygiene measures are taken very seriously. I have seen many patients undergo various endoscopic procedures without any complications and this is one of the safest diagnostic investigations.
I am actually surprised at your observation about instruments not being cleaned and complications. If the source of this observation is the internet, let me tell you that it is untrue. The internet is full of unverified, non-reviewed information, most of which is false.

2. I am willing to start changing the lifestyle to avoid fatty food and acidic food and exercise daily for 40 minutes, will this help my condition?
Yes. Lifestyle changes are as important as medication in managing GERD. You need to quit smoking completely (please seek help if you find that difficult). Along with the dietary changes and exercise, head end elevation of bed and avoiding a supine position for at least 2 hours after every meal, including dinner are also a must. When all these measures are followed strictly, you will definitely find good relief.

3. I am really worried here about any esophagus cancer symptoms?
Please relax as your symptoms in no way suggest cancer. Your age as well as absence of difficulty in swallowing, normal weight all cannot be present in a case of cancer of the esophagus. So please do not worry about this.

I would suggest that you go by your doctor's advice by increasing the dosage of your current medications as well as the endoscopy. This will show the severity of your problem as well as if there is a concurrent infection of the stomach. Based on the endoscopic findings, further management can be planned.
And please do follow all the suggested lifestyle modifications. This should take care of your condition.

I hope this was helpful. Feel free to ask queries.

Thank you.