I think an in person assessment from your surgeon or primary doc is in order. There is not enough info here, but possibilities include allergy to the post op bra (which you may or may not even be using), allergy to a medication you are taking. I doubt this can be solved on line.All the best
The best way to determine what size bra you wear is to go try them on. Each maker will be different. You may find some fit more comfortably than others. Find the one that fits.
Your breasts are pointy because the base is constricted. This can be corrected during breast implant surgery. You should be able to achieve a nice rounded look.