Large areas of unwanted white space

I am still very much a novice in Photoshop and I have a file that I've been working with for several years.  Every so often, I need to update the file with recent changes.  The file has a canvas size that adds 1/8th of an inch around the standard letter paper size for bleed, and I've never had a problem saving as or exporting this to other file types to fit on a standard paper size for non-professional printing.  However, as I am updating the file to incoroprate recent changes, I am getting very large white spaces to the right and bottom of my image that extends far beyond my canvas area.  I cannot seem to find a way to save as, print, or export without these large white spaces.  I also notice that Photoshop lists my document dimensions in the lower left-hand corner as 14.413 in x 11.913 in (300 ppi), which I'm assuming is where these white spaces are coming from.  But to my knowledge, I never modified these dimensions and this does not accurately reflect my canvas size.  I don't know if I somehow changed some settings or if a recent update of Photoshop has thrown my older files out of whack, but I have two nearly identical files that are acting the same exact way, so I don't think it's something that I've done in one file by accident.  Please help.