Same here. I have a bit of an oversupply issue and latch difficulties. 3hrly feeds during the day here to maintain supply in the beginning and that I've continued. If gaining at least you can rule out supply being an issue.
LC said to me today that the bouncing on and off is very common during the growth spurt times too. The banging of the breast is a way of them increasing the supply but if it lasts more than 3-5 days its probably something else.
I am now only feeding from one breast to avoid two lots of foremilk as it increases gut disturbances which can also cause the fussiness.
I don't know about you but there are just so many questions.......
Although FF isn't really any easier. I had to FF DS1 and there are still questions.