Regarding your first post: Sure you belong. I've seen a lot smaller dicks than yours here. If you're happy with it that's what counts and that confidence is what a girl is going to notice. I myself am 5.5 to 6 in., maybe a little bigger on a good day.
Regarding your last post: If you're like me you're a "grower" not a "shower" and after wacking a couple of times before a date it was probably tired and not quite up to it's full potential. Don't worry about it. Just learn to keep your hands off it if there's a chance someone else will be putting theirs on it later.
Lastly, don't compare yourself to the other guys on the site. This is a "big dick" site so most of the guys here are bigger than us and most of the girls like them big. Maybe you and I should go find the "Small Penis Support Group" site and post some pictures of ourselves there. Then we could tell everyone "Ha, tiny dicked people, bow down before our enormous, averaged sized cocks."
Welcome to the site and have a good time.