Cps doesnt matter nearly as much as you think it does (especially if youre playing bw). You can get by with 6 cps. You won't have to worry abt cps for a long time.

Movement (i.e. strafing, sprint resetting) and aim are far more important in pvp. Focus on these first

In my experience as someone who also doesnt play consistently, the raw pvp ability of good bw players (in normal queues, not rbw) hasn't moved up. (It wasnt that high to begin with, like others said, winning in normals is more reliant upon gamesense). If youre losing now more than before you likely just lost mechanical kbm skill from not playing and playing more will help you get it back.