Hello
I have gone through your question and understoond your concern.
You should know that 
Diabetic neuropathy has no known cure like all the other complications of 
Diabetes mellitus. 
Treatment for diabetic neuropathy focuses on relieving pain and slowing the progression of the disease.
It is very important to keep blood sugar within a target range.
This can help  delay the progression of diabetic neuropathy and may even improve some of the symptoms you already have.
Gabapenrin is a anti -seisure medication and it is used to treat nerve pain.
Based on current practice guidelines,the first-line treatment of diabetic peripheral 
neuropathic pain includes tricyclic antidepressants (amitriptyline, 
nortriptyline ). 
If these agents are contraindicated, newer anticonvulsants ( gabapentin, pregabalin) should be considered.
In my opinion,your doctor has carefully considered your functional status and potential adverse effects of gabapentin when he chose the treatment for your painful 
diabetic peripheral neuropathy.
So,My answer is:Yes,Gabapentin is advisable for pain related to peripheral neuropathy.It is a "good" treatement and you have no reason to be concerned.Stay in contact with your treating doctor for every problem you may have during the therapy.
Hope this is helpful.
If you have other question,feel free and ask.
Best regards.