Just use gvd:
// gvd backwards toggle (yaw 180 & pitch 360)

alias "gvdbw" "gvdbw_on"
alias "gvdbw_on" "kcc_fixedyaw 180; kcc_fixedpitch 360; alias gvdbw gvdbw_off"
alias "gvdbw_off" "kcc_fixedyaw 0; kcc_fixedpitch 0; alias gvdbw gvdbw_on"
bind "KEY" "gvdbw"


// gvd sideways toggle (yaw 89 & pitch 0)

alias "gvdsw" "gvdsw_on"
alias "gvdsw_on" "kcc_fixedyaw 89; kcc_fixedpitch 89; alias gvdsw gvdsw_off"
alias "gvdsw_off" "kcc_fixedyaw 0; kcc_fixedpitch 0; alias gvdsw gvdsw_on"
bind "KEY" "gvdsw"