It doesn't look too thin at all (if there really even is such a thing). It is tough to tell from just one angle, but you look, at minimum, average girth, and quite probably above average. Don't let all the gigantic cocks (many of which are fake, btw) on this site question your own dick. You have a big one there and be proud to use it.
BTW, many of the points about the downfalls of having a thick one are right on. I ought to know. I've never received a true blow job in my life because of my girth.