Welcome to HCM
We understand your concerns
I went through your problem description. I sincerely feel that there is nothing wrong with you. Several people do the penile enlargement exercises with several type of gels and oils.
The cases of nerve
or blood vessel damage have not reported till now from the exclusive cause of the exercise. Wherever there is damage, there is some other problems.
Therefore, stop worrying. Worrying may decrease the hardness of erections.
Hope this clears your doubts. Available for further clarifications.