LOL!
No, it's not a state issue and you can't explain how the Constitution says it is.
A virus doesn't give a shit if you're in Texas or Maine. Diabetes is the same in New Hampshire as it is in California.
Health care is a national issue because cancer doesn't recognize state borders.
Can you show me where the list of delegated authorities of Congress it says they have the power to deal with healthcare? The answer is no so don't waste your time. I can, however, show you where the Constitution says that powers not delegated to the federal government are reserved to the States.
Healthcare becomes a national issue when the Constitution gives Congress that authority not when bleeding hearts like you claim it is.