u/Historical_Amoeba_33

I’m currently a 34DD/32E and I find with every single bra, no matter what size, it cuts into my underarm and leaves bruises/marks. The straps also always fall down probably due to the way my shoulders are shaped. Is my cup too big? Should I go for a sports bra? Should I go for a bra with a strap in the middle of the cup rather than looping around from the underarm?
Any suggestions would be more than appreciated!