TSQL - Converting 1 line address into 3

Question

So ive found ive got a list of addresses (street, suburb, postcode) and added them into a table tmp_addresses. My idea was to split up the current addresses that are all in one line using the following code:

UPDATE  Client
SET     ClientCity = t.Suburb
FROM    tmp_Addresses t
WHERE   ClientAddress LIKE '%' + t.Street + '%' + t.suburb + '%'

UPDATE  Client
SET     ClientPostcode= t.postcode
FROM    tmp_Addresses t
WHERE   ClientAddress LIKE '%' + t.Street + '%' + t.suburb + '%'

UPDATE  Client
SET     ClientAddress2 = ClientAddress

UPDATE  Client
SET     ClientAddress = LEFT(ClientAddress, 3) + ' ' + t.Street
FROM    tmp_Addresses t
WHERE   ClientAddress LIKE '%' + t.Street + '%' + t.suburb + '%'

This does work, however it is unbelievably slow, i ran it for around 30 minutes and got 2 results when i searched for suburbs that are not null. Any ideas on how i can speed this up? Initially i tried using:

UPDATE  Client
SET     ClientCity = t.Suburb
        ,ClientPostcode = t.Postcode
        ,ClientAddress = LEFT(ClientAddress, 3) + ' ' + t.Street
FROM    tmp_Addresses t
WHERE   ClientAddress LIKE '%' + t.Street + '%' + t.suburb + '%'

But i kept getting errors saying ClientPostcode does not exist, not sure why. Either way the above would still take a very long time.

EDIT::

The second section of code now works:

UPDATE  Client
SET     ClientCity = t.Suburb
        ,ClientPostcode = t.Postcode
        ,ClientAddress = LEFT(ClientAddress, 3) + ' ' + t.Street
FROM    tmp_Addresses t
WHERE   ClientAddress LIKE '%' + t.Street + '%' + t.suburb + '%'

However it is still incredibly slow and is using 98% of the CPU.