We talked about it this morning, and I told him that I know that he still loves his ex, and that she obviously still loves him. He didn't deny it, in fact he agreed to still loving her. When they were together, they were so madly in love and dated for 10 months. They only separated because she decided to go to college in a different state. He was going to go with her, but ended up choosing not to. Right now, she is visiting from college. I told him I have no problem with them hanging out and still being friends. He tells me that he loves me, and in the end I'm the one who's going to be here, not her. In my heart, I know that he's trying to convince himself of that, too. I'm just confused and don't know what to do, because I love this guy a lot. He obviously still loves his ex, and me. I feel like he loves her more though since he knows her better. I don't know what to do. I need advice. Should I just power through it, and be there for him? Or should I leave and not put my heart in hurt and distress?

Yikes. Lots of patience and maturity needed here.

You don't want to be in a relationship where you might SUSPECT even that you were chosen only because his first option was not available. But at the same time, life is messy. He might like both of you, but one of you is his heart, and the other is his head.

You need to calmly acknowledge the possibilities, and tell him that you understand, but you can't be sure of whom he really wants. So give him space, if he really wants you more than her, he'll tell her that she has a good place in his heart, but you are now what he wants, to build his current future with you. Don't force him to say this (which is why you should give him space). He can't date you and be in love with someone else, that's unfair to all of you.

Give him space (not a breakup, you guys will still talk, but let him reach out to you more). Who knows what will happen in the future? All of you in this situation sound very young, so I don't think there's a lot of enduring, forever-type Love amongst any of you, so take this light-heartedly for now. But what you wanna gain from this is experience and maturity without too much pain.
If he does come back, they can't be close friends (not now) and you have to be part of that friendship, make her your friend. If he doesn't, don't be mad, just move along with your life.

Why did they break up again?

Oho!!!

This is absurd.U dont mind him being friendly with his ex,knowing fully well that he still loves her,infact they are still inlove.What do u want in a relationship?Ask yrself pls

Well...my own candid advice is just let him be for now and by so doing he might have a rethink...cuz you can't really force a guy to love you...and there's a saying that goes thus that where your heart is there lays your treasure...

Don't throw ur self at him else he won't see ur value. Let him clear his head on what he wants first. Definitely if u are the one,he will stick with u.