Organize Photos

Hello everybody,

My Macbook Pro is a little bit slow (since I updated to Mavericks....) so I searched what I can do to make it a bit faster...

And while searching I thought I could also tidy up my Mac, even though this won't help a lot..

So I started deleting photos (76 GB photos -> 48000 photos!) and I noticed that iPhoto saves my photos after importing too, so I have the orginals and the iPhoto version. That's not a very big problem when you have 400 photos... but I have like 20000?! so... I thought about deleting the photos I don't need in iPhoto and delete all the Orignials..

After deleting all the photos I didn't need in iPhoto, I started to figure out that I have more photos, photos which aren't in iPhoto.. even THAT is not a big big problem... I could just put them in and sort them... not a big deal...

but then, I looked in the folder of iPhoto (iPhoto Media Centre-> Masters, that's where it saves my photos) and all the photos I deleted in iPhoto are still there...

Does anybody know this situation and knows what I could do!?
I can't just delete the Orginals because that's very much work for deleting all the photos I don't need out of the folders and sort all the iPhoto photos complete new....

and I can't delete the iPhoto Media Centre too, because all the photos of my iPhone are there and nowhere else...

Does anybody have an idea for me!?