You might want to try a network config. It obviously can't reduce the true latency between your computer and the server, but it does affect what is sent over the connection and the client-induced artificial lag. Put something like this in your autoexec.cfg:
cl_cmdrate "40"
cl_interp "0.025"
cl_interp_ratio "1"
cl_lagcompensation "1"
cl_pred_optimize "2"
cl_smooth "0"
cl_smoothtime "0.01"
cl_updaterate "40"
rate "35000"
You'll probably want to mess around with rate, updaterate, and cmdrate, but the rest is pretty solid where it is.