Mel - are you right handed? I found that the side with the more coordinated arm was much easier to keep bub where he was supposed to be when using a football hold!
If this is part of the issue then you can use a football hold on the right and a cradle hold on the left, so that you are always using your coordinated arm!
Over the next few weeks Eden's mouth will grow and she'll get stronger and less floppy - which makes things vastly easier.
THe cluster feeding in the evening is totally normal. You can either give her the same boob until it feels empty or gets sore or the other one feels too full, or keep swapping. Whichever you prefer.
The most important thing at this stage is to manage your boobs so that they don't get too engorged for too long - so remember to express if she does have a big sleep and you feel like you are exploding!
Yay for you both!