SQL & PL/SQL :: REGEXP Digit Extraction?

I am trying to write a pattern that will return multiple numbers when it finds the string "My String" in a Text such as

Text String:
My String 5 Test Need a good regExp 34 to test multiple 12334 occurrences of the same 566 search string My String 3 hopefully this time My String 7 with three of these'

Expected Output:
5
3
7

I managed to write Regular expression that returns only for the first match as shown below.

select TO_NUMBER(REGEXP_SUBSTR(REGEXP_SUBSTR (vSearchText1, ('My String' d+')), 'd+'))