“I know that nothing I can do can affect the likely factors you are likely to face, nor your attitude and aptitude when facing them, but I wanted you to realise that I am sympathetic and supportive, in the common knowledge that this will make you feel better, no matter how objectively irrational that seems, therefore I will take the time to make you feel better, because I like it when you feel better”.
“I know that nothing I can do can affect the likely factors you are likely to face, nor your attitude and aptitude when facing them, but I wanted you to realise that I am sympathetic and supportive, in the common knowledge that this will make you feel better, no matter how objectively irrational that seems, therefore I will take the time to make you feel better, because I like it when you feel better”.
How about “I am sympathetic and supportive,” then?