It's very easy to create an ISO from your game CD:
1) Download and Install Iso Buster
2) In the program, to the left where the CD and its contents are shown, right-click on the first folder in the list (most likely just called CD or something like that) go to "Extract CD" and then "RAW".
3) Open ePSXe and go to File -> Run ISO and select what you made in Step 2
If there is any damage at all to the CD, Iso buster should say so. If not, load the ISO in ePSXe to see if it works anyway.