You'll be fine! Quite a few of my friends at uni went on two (or more) gap years and they're having a blast! The way I see it, your age won't become an issue unless you make it so. For the average rational human being, age isn't a determining factor when making friends; as long as you have a great personality (which I'm sure you do) you'll have no problem settling in. I know what it's like having a ****ty high school experience, but don't feel like you have to go out of your way to fit in. There's no need to change yourself to the point where you don't recognise yourself anymore. Many of the most popular people I know in uni didn't have the greatest high school experiences either. As cheesy as it sounds, just be you. And remember, with a large student population, there is almost always someone on the same boat as you- the odds are certainly in your favour!