I might be interested...again?

So, there was this guy freshman year. He was my friend's ex. Two weeks after breaking up with her, he asks me to Winter Ball. I said sure. But then my parents didn't let me go. So he was sad, but he took another girl. After that, we got really close (physically & emotionally). But there were some things that really pissed me off about him that I finally stopped talking to him. But he's sweet. He'd walk me to cl, walk me to the other campus for tutoring, phone calls, IMs, friendly PDA, etc. So, sopre year pes, and when we p by each other in the hallways, we just give each other this look. Most of the year is like this. Near the end of the school year, he starts going out with the girl whom he took to Winter Ball. At the same time, I start talking to him again, and telling him the reasons why I stopped talking to him. He understood; & he said he'd make an effort to change (btw, he actually has. I see it.) Anyways, they broke up a month later. He was emotionally screwed up, but I was there for him. But I didn't want to get on his ex-gf's WORSE side. I say worse because she already didn't like me since freshman year. :/ Idk why to this day. So, we're still talking, the last few months, & I got a couple core questions answered. He said that he really liked me, and didn't understand why I stopped talking to him. He said that his life would have been totally different if we went to Winter Ball together, & that he was going to ask me out that night. (but a question looming through my head is "Why didn't he ask in the later months? No 'perfect opportunity'?) So, we've been really close & talking every night again. He has a really really tough family life. & he just overcame lung cancer. But he still gets treatment and stuff every month at the hospital. But like I say to him, "I'll be here for you always, like you are for me.(:" Well, he's leaving for LA for this internship at this Thai business place, for about a week. I'll be gone too, camping with my best friend. We're texting, and at the end , I say, "I'll miss you (:" & he replies, " I know you'll miss me because I'll miss you too(=" What do you guys think? :/ I know most of your advice will be "DONT GO FOR HIM. HE'S NOT WORTH IT!" Or maybe that's just one of my friend's opinions.