If you were back together it would be VERY DIFFERENT.
The mistake you make is by thinking that it would be a better kind of different.
And sure at first it would be like winning, and hell who doesn't like winning. But here's the thing; you don't forget. When you're together its like a wave of releaf, but the moment you're apart you remember it all. The feelings of betrayal, you start feeling jealous and you wonder when things will fall apart again. Forcing you to start right back at the beginning all over again.
I haven't been posting here for the last month or so because I've been "lucky" enough to get a go at starting something "new" between her and I.
We don't say that we love each other, I don't know if she's seeing other people and I don't know if I'm putting up with this because I care for her or because I just don't want to be alone.
its all really just a willful confusion, hell she's even said that the reason she's "hanging out" with me is because she doesn't think she'll ever find anyone who's nicer to her.
truthfully I feel like I've been living a lie, projecting an image of myself that I think she might like more (I want to be this person too, but know I'm not there yet). Its A LOT of pressure.
My advice to you... You say that you'd be so much more positive this time round, and like he wouldn't I don't believe you. I don't mean to be a dick but its true. You have to start NOW with YOU, you might be aware of your faults but you still carry them and feel the guilt. you haven't forgiven them.
Be positive now. Don't focus on what you lost instead see that there is an entire world out there, full of nearly limitless possibilities. Embrace it and try to enjoy it.
Take it from me you don't ever get to return to that ignorant bliss that you had before the breakup if you get back together. You don't forget how you feel now and eventually you are going to be left again or you are going to be the one that jumps ship.
There's better out there, you just have to be positive and believe that youre worthy of it.
good luck to you