How small ? Only penis thats less than 4cm or two inches are deemed fit for any penile length enhancement. That too these surgeries rarely help as the enlarged penis is not very functional as normal penis.
Visit a urologist. Let them decide.
In obese a good 1-2 inch of penis remains buried in tummy fat. So if you have excess tummy fat...reduce it and your penis will gain good length
But what matters is performance and not size. So learn to perform good sex