Im dead tired working graveyard, but im gonna give my two cents.
This reminds me a bit of my first relationship. Which happened in my early 20's. So i read your TLDR and some of your post, what's obvious is how incompatible you were. Quite literally opposites of eachother, when you're in your first relationship it might feel like she's the world to you. But clearly. She didn't care about herself and she was a fat slob. This should never have led to a first date, You'll learn to filter them out in the not so distant future.
Second is frame, what everyone here have been saying is that you shouldn't have taken her back after the first break-up. Frame in a relationship is very serious, i'm pretty sure i've heard my LTR's pussy dry up when i've lost frame due to my temper. There's a reason they call this red pill on 'hard mode' managing your woman and keeping her happy while giving her a safe harbour or being her 'rock' is very difficult in the long run (and assuring that she satisfies you).
What you also need to integrate into your thinking is tolerance, and the lack thereof. I have absolutely zero tolerance for bullshit, and i've made this crystal clear for my woman, this might seem a bit black and white. But not having any leeway or letting shit slide puts you in a place of control and frame. I dont want to brake up with my LTR, i've invested in her. But i wouldn't doubt for a second if she broke any of the demands that i've set up. This might also come off as a bit harsh to you, but make sure that the door is always open, done like it? there's the door.
Then ofcourse you cannot just put demands like "WHY DID YOU BUY A PINK FEMININE FUCKING SOAP BOTTLE!?" this is real life.
Im talking about communicating with x's, not having sex for a week because she's not up to it, going out with the girls every weekend, flirting with guys etc. Just general shit like that, Which i make sure she understands that i take very seriously.
Keep in mind.. sleepyness. Read the sidebar and once you're done with that just shoot with any questions.