This will still have to be guesswork but check the 'Horizontal Scale' in the 'Character' panel....follow Sams instructions on how to open that...post #14
The default for this is 100%.
With an image of that size and a font size of 24pt you should be able to see the text clearly so it must be something other than the font size.
Without the info we've been requesting from you its difficult to say what to suggest but you could also try resetting the character from the 'Character' panel by clicking the small icon in the very top right corner of the panel, (see image), and choosing 'Reset Character'.
This will unfortunately reset the font too but this will reset all the parameters in the 'Character' panel.
At least by doing this you are starting from a clean slate....of sorts.
Regards.
MrToM.