HELP with work love triangle!!!

A few days after I turned 17, I began working at this small restaurant in my town as a waitress with many of my already close girl friends. My first day there, I was taken aback by the attractiveness of one of the "bus boys", we'll call him Justin, and I immediately wanted to talk to him more. My friends who worked there for longer than I had agreed he was attractive and encouraged me to speak to him. I gave Justin rides home from work every time we worked together for a while, because he got into an accident and did not have a car. I really started to like him. In the meantime, another guy at work, we'll say Robert, started talking to me a little bit and obsessed over my car, because he's super into cars. Robert was the "stud" of the restaurant and many girls liked him. Extremely soon after beginning to really talk, Robert and I started dating. After a short period of time, Robert broke up with me without much of a reason besides a "feeling" he got and I was distraught. He was my first boyfriend and the breakup came out of nowhere. A few weeks later we hung out again and discussed getting back together, but nothing official happened. In the meantime, Justin and I rekindled our old flame and after we hooked up at a party and our drunk feelings came out, he explained how Robert knew how much he liked me originally and was so upset that Robert "stole" me from him. Robert found out that we hooked up, and said that he definitely decided we will keep our distance from hereon out. Justin and I have been hanging out a lot lately since I accepted that Robert and I would never be together again, and I like it, but it's not the same as it is with Robert. Last night, Robert appeared out of no where and we went for a late night drive. I know where my heart is, but Robert is so turbulent and likes me one second and not the next, and Justin likes me wholeheartedly, but I just don't feel it with him. What do I do?