What Causes Vein Prominence With Bulging On The Penis Shaft?

ok this might sound wierd but i have been masterbating for a long time, day after day every day sometimes more than once. in the last month i have noticed a vein popping out on the left top side of my penis underneath the head, it seemed to get longer expanding toward the right side and angling diagonally towards my body slightly. then a couple days ago i noticed while i was urinating that that part of my penis was swollen all the way around from top view anyway. i though maybe i busted that vein the night before masturbating, but i searched online what happens when a vein bursts and i have no pain or discoloration. i masturbated that night and saw when hard it was still swollen its like that part has more girth now i have the type of penis where my head is bigger around than my shaft and im circumcised but with the swelling the part under my head is just a little bigger around than my head now looks kinda funny to me. anyway i noticed tonight when i masturbated that the vein now goes from the left side around to the right side. but what im wondering is, is my penis going to look like this always now or is there a problem or any feed back you can provide would be appreciated. oh and when im soft the skin where the vein is feels really soft and rubbery kinda almost like sex toy material and when soft the vein is not bulging.???????????????