Many on here have had great luck with Limcomin despite copper problems, so I would not abandon it until your really sure its causing you troubles.
That being said, Limcomin was NOT good for me at all. I suspect it was the copper in it? But I feel much better having stopped it. I have replaced it with Citramins II from Thorne. Again, I have made these switches recently so its hard to say for sure if I can get similar benefits from the CitraminsII. Also, what has worked for me may not work for you, So I would encourage you to tread carefully.
In terms of lowering copper but not lowering sodium - Molybendum is supposedly the key there. Moly raises sodium AND lowers copper. Manganese could be good there too. Citramins has both in it btw.