there are a lot of cool people around always around the closing parties. try to make some contacts already on here so you have a few people you can meet while you're over. then, if you're easy going and open enough you'll meet a lot of people just like that and you still have the opportunity for some 'me time' if you want it.
before I came out to live here I went to ibiza alone a good few times, never had a bad holiday and always met cool people. go for it.