Hi, Your ratio is right.
but, dont add anymore peroxide. Remember, peroxide is mostly water,
and that will stall the etching. The best way to tell what you need
whether it be more acid or peroxide is to do a titration test.
heres a link:
http://members.optusnet.com.au/~eseychell/PCB/etching_CuCl/index.html#analysis_acidThis will tell you how much acid to add to the mix to bring you back
to the 2:1 ratio
hope this helps!
Joe