Answer: Unfortunately, based on your description I am not certain why your rose blooms are lasting only a very few days. The blooms could be fading extra soon due to a disease problem such as botrytis or a pest such as thrips, or due to water stress, for example, or simply because each individual bloom doesn't last terribly long by nature.
To encourage your rose to rebloom, you may want to review the correct procedures for deadheading. Here are instructions from the American Rose Society.
If you feel there is a problem with your roses, I would suggest you consult with your local Rutgers county extension to see if they can determine what is happening and suggest how to improve their performance. They may appreciate a photo of the overall plant as well as closeups of the blooms. I am sorry I can't be more specific for you long distance.
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