My name is also severin. my family has traced its roots for almost the past 1000 yrs. my family is from Norway. If you look into Norwegian websites.
you will find thousands of Severins there. I have been told that Severin is originally french but do not believe this. I believe that when the "vikings" had extended their trading (or raids)the name was passed to several areas of europe. The name severin is traced back to members of my own family from Norway 840 years ago. it is possible that your own family is from romania, or any number of places. And had taken The name from Northmen who had settled there. The vikings had settled in various locations throughout europe. There are a surprising number of names that though believed to be native to a specific country, actually have Norwegian roots.