HI - I've decided to retire my left breast

It is worthless! He can't latch because of a flat nipple
(I've seen 3 LCs, tried shields and shells, tried everything).....I've been feeding him off the right breast and pumping the left. Additionally, there are very few milk pores on that side so I get less than 1 oz at every pump.
I'm SO done with the feeding AND pumping only to get 1/2 oz.....and would like to retire it. What do I do? Just reduce number of pumps each day gradually? Even though it's a small amount of milk it does get quite sore between feedings so I'm concerned I will spur mastitis or something!
Thanks in advance, reallllllllllly appreciate it!!