varicose vein/lump on end of penis shaft, just before penis head

[yycguyy]

Wondering if anyone can help with this?  I don't remember how this started but I think I was having vigorous sex one time and this happened.  I have about 3/4 of an inch of varicose vein at the end of the penis shaft and just before the penis head.  Doctors tell me it is nothing but it is in my head right now.  What the problem is that because of this varicose vein, it is causing the skin around the area to be red and purple like colours.  Every time after sex, it gets more red and sometimes looks like a bruise as well.  I am at my wits end trying to figure out what to do.  
Again, 2 doctors have said this is fine and I can continue as normal but when it is always red and irritated, it is tough to feel normal and am always afraid to have sex now fearing it will make the varicose vein larger.....will the vein get larger and is that a problem in the future?  I do not mind or care about the appearance, I am more concerned about the redness and the bruise and the skin irriation.  FYI, I am putting a special cream on it, called PROTOPIC and this seems to help with the redness.  Any help would be much appreciated!!!