I'm trying to say all of this in a way which will be helpful to you. Please consider what I'm telling you carefully:
You are very young. You need to grow up. A lot. All of us must face growing up. I did. My friends all did. I hear a lot of this stuff: "He's my high school sweetheart," and "he's my best friend." Stuff like that. There is an attachment to making things be "the way they're supposed to be." Somewhere along the line you fell in love with this romantic vision of how your life should be. You can't force it. Your views on love and relationships are immature (I don't mean this as a put down, but I have to say it in a direct way so you will hear me clearly).
If he's saying he doesn't love you, that's a biggie. I can't understand why you're still hanging around if he doesn't want to kiss you and he talks to you like that.
By your own admission, you expect things to be rocky. That does not need to be the case at all. Long-distance relationships can be challenging, but they should not be rocky. Your love letters and phone calls should be full of sweet talk, full of your dreams and your aspirations. Otherwise you're fooling yourselves.
It is not a good idea to move in with someone when your relationship is not solid. This just makes everything else harder if you have to break up. If you had a better idea of where you're going together as a couple, enjoy each other's company, bring out the best in each other, etc, etc, then that would be different. This does not sound like your relationship.
Pay very good attention to how he is treating you now. He is showing you what your future together will look like. What kind of husband will this make him? What kind of father will he be? Are you paying attention? He is not going to change. Once the stress is on (career, children, etc), you have been given an accurate sample of what you'll get more of once you settle down. Is that what you want? Only you can decide.
What is he going to do if his running career does not pan out? I've been around a long time. Truly so few make it to the top--your Bob Kennedy's, Ritzenheins, Halls (I could name hundreds of All Americans that did not make it). So, so many are telented in high school, and even college, but so few really have success. And that success is so short (alas). What are his pursuits outside of running? What you describe about his college choice does not sound very promising. How are his marks? Does he have passion for his major field of study?
If you stick around--and again, only YOU can decide, he is giving you dozens and dozens of clues about the kind of person he is, about what your future together will be like. Do not turn a blind eye to preserve some fantasy you might have in your head about about your dreamy future together. Do you deserve better? Will you want more out of a man?
Yes, love is work and requires two people committed to making it work, to being open and giving their best to each other. It should not be rocky. It should actually be pretty smooth as far as getting along goes. It may take a major plan for you to just have time to have a date together, but making that plan should not involve heated words and unaffectionate tones. People say, "Everyone has arguments." Okay, I'll give you that one. However, those arguments should be few and far between, especially when you're in college and your life is relatively carefree compared to the stressors of a mortgage, careers, and maybe children who are depending on you to give them an environment where they can grow up and not be made into psychos by their raging, dependent, needy, high-maintenance parents.
Kids in high school think they're in love. Sometimes they are. My own parents will be married 50 years in April, and they were h.s. sweethearts. They are the exception though. If I would have married some of my high school loves--holy crap! I actually had a few good relationships (never stayed with anyone I continually faught with), but they were still high school romances--we were two kids with similar goals moving along together at roughly the same pace. Until our relationship(s) reached that fork in the road. We see each other at h.s. reunions and remember our good times fondly. But I wouldn't swap one of them for the person I married (we met when I was 24).
You've been in a relationship for what? Three years (at least)? Isn't a wonderful opportunity presenting itself? You might now have time to stand on your own two feet, to make decisions just for yourself, to be your own best friend, to learn about yourself and this big world of ours. You'll look back next year and see that you've grown. How satisfying will that be!