Community Shaders and ENB don't actually conflict the way you're thinking - the issue is usually that you've got both trying to do the same job at once, which tanks performance and looks muddy.
First thing: what ENB preset are you running? Some older ones have water shaders baked in pretty aggressively. If Community Shaders is also trying to touch water, yeah, you get that washed-out mess. Check your ENB's ini file - there should be toggles for water, effects, post-processing, stuff like that. You might need to disable the water module in your ENB config and let Community Shaders handle it instead.
Also make sure Community Shaders is loading after ENB in your MO2 left pane. If it's above ENB, it gets overwritten and you won't see its benefits anyway.
The performance hit you're worried about is real though - running both at full blast will tank an older rig. I'd suggest disabling some of the heavier Community Shaders features (check what's actually enabled in its config) and seeing if you can strip down your ENB preset a bit too. You don't need both doing ambient occlusion, bloom, and color correction simultaneously.
What's your ENB preset called? Might help narrow down which specific settings are clashing.
