I feel you on the smoking too much weed tip. This is the second semester I've been out on my own, and I've just been finding more reasons to blaze. First it was just on weekends, then just when I didn't have HW, then just after class, and now it's just whenever I'm bored haha. But yeah, I definitely feel myself getting lazier, I need to cut back for sure. Honestly just try not buying it and smoking when other people have it, that's what my girlfriend does and it works out for her. Or, just do what my friend does, and just pick up for the weekend and blow through it, then during the week get your grind on. It's all about finding a balance between your vices and your real life, and making sure your vices don't become your real life.
Oh, and happenstance, that's a shitty situation. The way you're going about it seems good though, I agree that sometimes getting too physical too fast can fuck up a good thing. Odds are, if she agreed that you should go then she probably felt the same way, if she was really tryna get it in I assume she would've hinted that you should/could stay. Just don't beat yourself up about it, if she's still not feeling it after a couple months, then it might be time to just pursue other options.