Iphoto Question Please Help!

#1 Woke up yesterday and noticed there are many pictures missing from my Iphoto library.

#2 The folders are still there but there are NO picture in some of them EVEN though my total picture count remains the same. About 25k pics.

#3 I do a google and some forums suggest "rebuilding" the photo album THROUGH my Iphoto Photo Library.

#4 I go ahead and start the rebuilding process which seems conceivably at the rate its going, it might take maybe a full day or more!!

#5 My laptop FREEZES for some mucked up reason at about 5500 photos. I am forced to force quit Iphoto and RESTART the whole process.

#6 Now during the "rebuild" process. The process stops at and ONLY recognizes up to the 5500 photos.

#7 Now my library ONLY says 5500 photos instead of the 25k

#8 All of my photo FOLDERS still remain.

#9 A little tidbit, I don't know why but my external 2tb hd is somehow connected to my Iphoto, where if my EX HD is not connected I will be missing many photos from my mac laptop Iphoto Library while disconnected.

#10 2 things, I have not backed up my library since Dec 2010, BUT i also have added very little photo since then.

PLEASE HELP ME KIND MAC PEOPLE, What can I do? Where have all my photos in my library gone? Why will it only rebuild now only to 5500 photos. Please shoot my some ideas and help if you can. Thank you very much for your kind advice and help! Humbly "Devastated" for these photos are work and family irreplacable