Breast abscesses, though rare, can remain undiagnosed. Ultrasound can be used to determine if an abscess is present and if so, where it is located. It would also be wise to also have some blood work done to rule out the possibility of anemia, which also plays a factor in repeated mastitis. I was not clear if you were saying that you were experiencing pain in both breasts at the same time. If it does occur in both breasts at the same time, it is particularly important to visit your HCP and determine the pathogen involved.
Bilateral mastitis can be the result of strep, rather than the more typical staph infection.
Drop one feed every 3 or 4 days, waiting until you are comfortable without expressing any milk in between feeds. Express your milk as needed for comfort. When you drop a nursing session, express just enough milk so that you remain comfortable in between feeds. In the beginning, you may need to express quite a bit. Over a period of several days to a week you should find this amount decreasing until expression is no longer necessary.