Try the following you your only library:
Using iPhoto Library Manager to Rebuild Your iPhoto Library
1 - download iPhoto Library Manager and launch.>Click on the Add Library button,
2 - select the library you want to add from those in the selection window.
3 - make sure that in the rebuild window the checkbox "Scavange orphaned photos" is checked.
4 - now that the library is listed in the left hand pane of iPLM, click on your library and go to the Library ➙ Rebuild Library menu option
5 - in the next window name the new library and select the location you want it to be placed. Click on the Create button.
Note 1: This creates a new library based on the LIbraryData.xml file in the library and will recover Events, Albums, keywords, titles and comments. However, books, calendars, cards and slideshows will be lost.
Note 2: Your current library will be left untouched for further attempts at a fix if so desired.
OT