I Have Been Taking Gabapentin For Six Weeks Now For

I have been taking gabapentin for six weeks now for serious pain due to a trapped nerve in my spine.
I have now got over all the initial side effects dizziness etc, I have noticed a steady weight increase although
my appetite has decreased. This is very worrying as i'm sure I will be waiting a long time for an operation.
I was in so much pain I daren't reduce the dosage.
Please advise.