I think (think not know) it’s that you’re not yet mature enough to handle a long term relationship. I dont mean that in the negative, derogatory way that the word “immature” is usually taken in, either.
When I was 18 I was the same way – the world was my playground, I didn’t want to “settle down” with someone (that whole concept seemed boring to me) and it seemed like no one was ever good enough for me (like you, I’d find myself “bored” in situations I shouldn’t be). I didn’t know myself or where I belong and I barely had a chance to see the world with my own eyes — I hadn’t been to college at that point or off “on my own” and everything had been down for me at that point. Marriage and commitment to me meant a lot less back then than it does to me now.
You may love this guy with all of your heart but I dont think the timing is right – if it were, I dont think you’d even be able to utter the words “I’m bored”.