Have you seen a doctor? That's the first think you should do if you are this scared, right?
Don't attempt to narrow your own veins. That's definitely not something you should ever try on your own. Let a doctor do treatment, not yourself, especially on your penis, veins, arteries, etc.
We can't tell you what you have here, but you really should go to the doctor. It's been happening for 2 months. It's not going away. Go get it checked out.