Thanks for your query,based on the facts that you have posted it appears that you have pain in pain and burning in penis after ejaculation.
You have undergone surgery of Orchidectomy for torsion of testis and a silicon prosthesis
has been implanted in your scrotal sac.
This is in no way related to your pain in penis.
During erection and ejaculation blood flow to the penis is increased to 20 times more than normal blood flow resulting in to congestion of entire penis and urethra
The pain that you have is due to congestion of the penis and there is nothing to be worried about .
Drink more water so that this congestion will subside with passing urine after ejaculation.