I'm in college now and there's a huge variety of students. We have the youngsters who started when they were 18 (like me), but we have people in their 60s who are only just now earning their BAs. 19, like someone else said, is not old at all. No one would notice or care. It's very normal for people to start college a few years late or even a few decades late.
I'm 20 years old now and just about to finish my third year of college. In the course of my studying, I've had both the experience of being a slightly older student in a freshman class and being a slightly younger student in upper division classes. It made no difference (though I had to fight my way into one of the upper division classes because I technically didn't have enough credits--I passed with flying colors I might add). No one even notices my age, because you really can never tell with college students.
I don't think you'd regret going to college. It's a lot better than high school, at least in my opinion. The people are generally brighter and they're in college because they want to be instead of because they have to be. You only have to take subjects you like to take and you have the freedom to decide whether you want to go or not. It's not for everyone of course, and if you don't enjoy it that definitely doesn't make you stupid. But for me, college has been a really good experience. I hope it will be for you, too