Due to reasons beyond my control my only sexual relief comes by masturbating. What was once a means of quick relief has now become a serious and extremely enjoyable activity. However, I have two questions that worry me.

I masturbate several times a day, I have now discovered the delight of being able to rub my penis for anything up to forty minutes without ejaculating. The feeling is exquisite. At the end of each session I am very aroused but often I find swellings which are painless under the skin of my penis which are only evident when I am erect. As I produce a lot of clear slippery fluid which acts as a good lubricant I was wondering whether this could cause the swellings?

The other slight worry I have is by constantly stimulating myself and not allowing myself to ejaculate semen for a number of days in succession is this harmful?