Hi and welcome!
By your measurements you aren't a 34 bandsize and I think 32a was too tight because the cup was wrong also in the store it should feel very tight in the band you shouldnt be able to fit more than a finger under you band also you should always start on the loosest hook you should be wearing more like a 28c or no bigger than a bandsize of 30b/c.
This will really help with your nbe to wear a good size the wrong size can distort the shape and even make breasts smaller.
I wouldn't go by bra size go by width of the front of your chest try to measure how wide your breast tissue and choose a size dome with a base diameter of slightly bigger, if your cup is too big its much less of a problem than it being to small the widest cup you can use will give better swelling, I would guess at least a large that's only 5 inches wide not a big size in anyway.
By your measurements you aren't a 34 bandsize and I think 32a was too tight because the cup was wrong also in the store it should feel very tight in the band you shouldnt be able to fit more than a finger under you band also you should always start on the loosest hook you should be wearing more like a 28c or no bigger than a bandsize of 30b/c.
This will really help with your nbe to wear a good size the wrong size can distort the shape and even make breasts smaller.
I wouldn't go by bra size go by width of the front of your chest try to measure how wide your breast tissue and choose a size dome with a base diameter of slightly bigger, if your cup is too big its much less of a problem than it being to small the widest cup you can use will give better swelling, I would guess at least a large that's only 5 inches wide not a big size in anyway.