Please look at the following:
Dear Katharine (very dear):
I've had moments of despair during the last week which have added years to my life and put many new thoughts in my head. Always, however, I have ended on a cheerful note of hope. based on the realization that you are the person to whom I return and that you are the recurrent phrase in my life.
From Letters of E.B. White
From the context here, I think the phrase "add years to life" means that "it makes me worry and makes me feel years older" but I searched everywhere and cannot find another instance where this phrase is used with this meaning.
I have searched all dictionaries I have access to: OED, OALD, Cambridge advanced learner's dictionary, and American Heritage Dictionary, but cannot find the meaning for this phrase.
I also Googled it to try to find how it is used in different contexts. In all the cases I have found, it appears to mean "to make me live longer."
Can someone let me know:
- can the phrase mean "it makes me feel years older?"
- where else is it used with this meaning?