TL;DR story, you can skip to the bottom and just give me advice:

Well, it all started nearly 6 years ago, but we got back together about two and a half years ago after a long break where we both saw (lots of) other people. We met on the internet, but he moved to live with me a year ago. He's been living in my parents' house since.

The plan was to both get jobs and move out together while going to school. We were both excited and ready to move on with our lives, or so I thought. So far, I'm the only one with a steady job (he keeps quitting his jobs). He's also flunking his classes and just went back out of state right before finals week, so I'm assuming he's going to fail and doesn't care. He doesn't really give a fuck about anything except smoking (my) weed and stealing wine from the grocery store. In direct contrast, I'm a perfectionist. I will sit down and study for 12 hours straight if that means I'll get the 4.0, which he makes fun of me for. I even spent $500 to take us both back to his home for his birthday this year. He bought me nothing for my birthday this year. In fact, he's forgotten my birthday before.

He has made so many stupid decisions that got both of us into so much trouble. I don't even wanna get into it, but let's just say I got my first-ever ticket thanks to his stupidity. He dented my parents' car and then put the wrong kind of gas into it, resulting in my parents having to pay $600 to fix the damn car. I honestly hate him these days. It's like he can't do anything right, a stereotypical loser. He's not even nice about it. He doesn't apologize when he hurts my feelings, or even when he does the little things, like when he threw away my math notebook. I'm not a perfect person by any measure, but I do work hard and generally try to do the right thing. I can't say the same thing for him.

When we first got together in my freshman year of high school, he was a very sweet kid who struggled with the same problems I did. I thought we were soulmates. He always made me happy back then. It seems like our relationship has since died a slow and painful death: a steady degradation into complete misery where both of us hate each other. It's been shitty for a long time and I really hate to be that girl stuck in a bad relationship that she refuses to get out of -- but it's been SO HARD to admit to myself that he's changed as a person. Somewhere along the way, he became more selfish and manipulative, his once-charming clumsiness became irritating, and he stopped making me happy. </3

Has anyone else ever known someone for so long who completely changed as a person, and how did you get over it and stop running back to that person?

You already know it's over. Hell, he probably knows it, too. You're just delaying the inevitable, and it's to no one's benefit. You said it yourself - you're both miserable in this relationship. The sooner it's done, the sooner you can both move on and hopefully be much happier for it.

To answer your question: Should you ever feel like you've made a mistake and want to run back, you'll have to force yourself to face the fact that you're not longing for him - you're holding onto the memory of who he was. Realise that person no longer exists, and you will be able to heal.

pretty much already said it.

I'm assuming if you met in freshmen year, you meant high school, and its safe to say ya'll are in college now? People change, some for the better, some, sadly, for the worse. The safest thing for both of you is to leave the relationship. I know from experience after so long its hard to just up and leave. I was with my ex for close to 7 years, and that was both of our longest relationship, but he was mentally abusive. Sometimes though, for you're own health and safely, you need to do whats best for you. And if that means leaving this guy, then leave.

But its like Narceu said, you're holding onto who he was and possibly hoping he'll change back into that person. That doesn't always happen. Yes, when you first leave it'll hurt. Despite how my ex treated me (he called me fat on my wedding day) leaving him, hurt for the longest time. And when hubs and I were still dating, I'd often run to my ex for advice. Honestly, its a toxic relationship and isn't healthy for either of you.

I read your entire post. Sorry for the late reply.

When you've had enough of worrying about all the bullshit and would rather you just worry about yourself, you'll know. You'll know it, and it's still gonna hurt, it's still gonna be shitty and probably dramatic. And very emotionally draining. This is someone whom you've grown up with, as well as tried to come together in love with. I know people say "all relationships have their ups and downs" But I'm telling you from experience. When you know, you'll just know. It'll be that THING again, or THOSE[/B] things. All those ridiculous things that continue to hinder your relationship.

You have two options. Both aren't easy. 1)You either truly communicate and come to an understanding and work through the issues for a while and change lots of factors to try and make things work, and change more factors and talk about more issues and more feelings and try and make things work, and.... and it [b]STILL might not even work out. OR 2)CLOSE THE BOOK (and start a new chapter in YOUR life)

if you haven't already.. dump him.