concerned about my iguana.

Question
my iguana has been sick for about five months,he has been to the vet twice i am following all of the instructions and he does not seem to be getting any better,some of his symptoms includes swelling of the mouth loss in appetite,weakness,breathing complications,i have became very concerned because i have tried everything,from force feeding to frequent vet visits.if there is anything you can tell me it will be very helpful i am desperate.thank you for your time and concern.

Answer
 You did not say what the vet found.  Was the swelling from an infection, mouth rot, tumor?  Is the swelling compromising the breathing or is that a separate problem?  
 I think you'd do well to join the Yahoo group called Babyiguana.  There are wonderful people there including those who have had rescue iguanas that they brought back from near death.  The people that I learned much from.  They have slurry recipes for syringe feeding to give your ig more nutrition per gram.  Sometimes igs will try and give up when they are sick and some of these people gave them back the will to live.  Joining this group will give you a lot of support, I urge you to consider them.