Don't fret! My son also has a hemangioma. It was just a tiny red mark on his neck at about 3 weeks. His doc said it would get bigger, redder, and raised-and it did. The doc also told us these typically go away by 1 year of age. My son is now 6 1/2 months old. It is starting to get less red and less raised.
I know it is hard to constantly answer the question "what is that?". And I know it will be hard to do, but just wait it out. I will get better.
If your babe's doc isn't concerned about it, then don't spend too much time worrying about it!
By the way, the falling in love with your son will only increase with each new milestone he reaches. Just wait until he starts squealing with joy! There's nothing like it!