It doesn't seem scary skinny, Cormac. I have a son who's 6' 2" and I think he's between 150 and 160. He's very slim but not unhealthy looking. He looks good! He's a young man of 21. His twin brother is 5' 11 and he's under 170. He looks great, too. Your pant size doesn't seem too terribly small either.
I think you are going to be the best judge. How do you feel? Aside from being depressed. Hmmmm.