I just finished reading this thread now and damn near cried a couple of times.
I'm so pleased for you, I ♥ Maria! It's wonderful to hear about how empowering and positive you've found coming out to be so far.
I don't have much of a coming out story to tell, as it was a process spanning a few years and it was a while ago now, with the memory fading and all. I remember it got easier and better all the time though, and it did have a huge impact on my personality - went from being nervous, shy and mousy to being completely at ease and quite outgoing. Again, that took a few years. I hope that if you have any shyness/nervousness issues, by coming out, you can bring yourself out of your shell too.
I did something similar to your plan of telling your parents when you go away for college. I would recommend that - distance, both spatially and headspace-wise, means that if they have a hard time handling the news at first, their opinion won't be 'the be all and end all' for you anyway.
My only bit of advice would be to try to come out first to those you're more sure would be cool with it. If and when you do come across friends, classmates, etc. who aren't so supportive, you might find it a lot easier to deal with their reactions when you already have a fair number of people around who do support you.