try and use these commands for the freeze
cl_updaterate 100
cl_cmdrate 100
cl_rate 10000
rate 25000
fps_max 720
developer 1
now the lag is supposed to drop to 10-20 ping
actually the lag maybe a server problem or something that you have open while playing
for example many times my antivirus updates when i play cs.
.
after using the commands the fps myst have been up significantly and the lat is supposed to drop a bit
lag is caused by server and other ppl that lag in server causing you to lag too!
EDIT:check the graph(net_graph 3(i prefer 3 you can change it to put the graph to the place you want)) for your ms while playing
if the ms is rissing more that 100 this is what causes your freezing.
ms is not upon server is just about your graphic card so....