Problem witch implementing big automaton

first, remember the counter use is not going to solve your issue much since the associated logic is huge.

--pseudocode
-- divide clk process
process
begin
   wait until clk = '1';
   divideclk <= not divide clk;
end process;
 
then use that divideclk as enable:
process
...clk edge ...etc
if divideclk = '1' then
 
   fail_edge <= '0'; --default
   case count is
       when 0 =>
           if stream = "00101110" then
              count <= 21;
           end if;
       when 1 => 
           if stream = ....
              count <= 102;
              fail-edge <= '1'; --non default
           end if;
 
...etc