I often find myself in positions with the Carlsbad pawn structure, and I really struggle to come up with a plan. I am usually the one with the pawn chain pointing toward the queenside, so I assume that I should be focusing my play over there with things like the minority attack. However, I have recently found the minority attack to be unsuccessful for one main reason. The moment I push my b-pawn to b5 in the position shown below, white can respond with b4, instantly shutting down all of my play. Even though b4 creates a hole on c4, I also have a hole on c5 which my opponent can take advantage of with his knight. At this point, I have no idea what to do, and my opponent can play on the kingside with moves like f4-f5.
Question: How should black (in this case) play after white plays b4?
This is the type of position I get into as black.
[FEN "1K1RR3/P1PQ3P/1PN1BP2/4P1P1/1B2p1p1/3pbn2/ppp1nq1p/1k1r2r1 b - - 0 1"] [startflipped ""]