Hello Knox,
I am not sure of the actual durations units spent in Berlin, but you are probably about right at 3 years.
I am afraid that I don't know enough about these rotations to be able to help you with the names of the units in Berlin at the time you were referring to.
The following website is devoted to Post 1945 British Army operations.
http://www.britains-smallwars.com/main/index1.html
You might find that by emailing them, they can put you in touch with servicemen who served in Berlin who can help.
It cannot of been a lot of fun realising that your role was to act as the first Speed Bump in the way of the Red Army.
Regards
Nick Balmer