lemon I booked a private scan at 10 weeks this time (combination of not getting round to it sooner, and wanting to leave it long enough that I would definitely see a hb if there was one). I was supposed to be having an early scan (offered by GP) but hospital were muppets and it never happened so I just paid privately. It helped to have the scan then - reassurance that I was definitely off the starting block so to speak! Like angel, the scans became a stepping stone, I never thought further ahead than the next one. I expect for you, like me, the "big" scan and hardest will be the 20 weeker, but they are all scary and wonderful. The temporary reassurance after each one made the fear before all worth it. And even if the scan had been bad news, it would be better than not knowing and fearing the worst anyway (for me, at least).
angel fantastic as it is when they sleep when you're out, I do always have a moment of "arrgh, why am I here, she's sleeping, I should be in bed!" 
I'm not sure if you've come across [http://kellymom.com/bf/normal/growth-spurt.html kellymom]]? I've linked you to the page on growth spurts and bf. If she seems really hungry, it could be that she's trying to drive up your supply - bf is very much supply and demand. It might be worth letting her continue to suckle after each bf for a bit before going onto the bottle, even if you feel pretty empty, as this will tell your body to start upping production. If you do this for a couple of days then you will start making more milk, and may need less bottle top ups after bf's. (cheese please come and correct me if I am talking crap!)
Always worth getting your latch checked if you're not sure about it - as she grows she may start doing it differently/you may hold her differently, and so the latch can change without you really noticing. We had to start again a bit at 4 ish weeks as I was getting sore again. Had some advice from a bf counsellor and spent some time in bed skin to skin, paying proper attention again to the latch and it went a lot better.
Can you get the bf counsellor to come for another visit to talk about mixed feeding/supply/latch?
Am hoping for a nap this afternoon when Freya has her long doze. Yesterday I stupidly sat on the sofa for 3 hours with her asleep on me whilst I browsed AIBU 
Daft idiot!