MacBookPro Software update on 4-10-15 included awful iPhoto change....how do change it back??

Hello Apple,

I have had my MacBook Pro for about four or five years now and until now have had no problems with any of the miscellaneous updates it does every once in a while. However, tonight, April 10, 2015, I updated my laptop software with the "OS X Update version 10.10.3" and what it did to iPhoto is not only a complete one-eighty of what it used to be, but it's impractical, messy, and has destroyed the organization process I had going on before the update. How do I get the previous iPhoto back? It looks like the last version of iPhoto I had was 9.6.1 and I installed it on April 1, 2015.

I look forward to hearing back from you about how to fix this.

Thank you so much,

Carly Jones