If we are truly a country ruled by the majority, then it would seem un-American to think we should all have good health care. Fortunately, we are not simply ruled by the majority, for too many of us think it wrong to "socialize" pretty much anything. Evidence thereof is presented in some of the Answers posted.
I think you already know the answer to your own question. I applaud you for asking it and for the not-so-subtle message it contains.
Really, it is, if we consider the Constitution itself, un-American to deny access to health care for all Americans. Affordable is a subjective term, but if we can get top-quality health care to all of us, then we have taken a grand step in the right direction. I have long felt that lack of quality health care is one of our most pressing, crucial needs. It may well be the most pressing and crucial.
Do a little research and you will find Constitutional support for the belief that this thing called health care is a RIGHT, not merely a privilege for those with money or the "right" jobs.
And it certainly is a NEED.
To answer your question directly: You are NOT un-American for believing what you do; indeed, you are the right kind of American.