mad about losing events from iphoto with the new "photos" app

I have over 300,000 pics that where neatly organized into iphoto events. I stupidly updated unknowingly to the latest osx and poof! my events are crap now. I found some half assed somewhat similar looking attempt at what where once events in the app.. but the pics are not how I had them at all.. I have art with family funerals, animals, vacations and inappropriate things together in no way does it make any sense and I cannot pull up a pic i want with any ease because I have no idea how to find them anymore. I am really upset about this. please if anyone knows a way to restore some semblance of the events I previously had, let me know... But yeah, I did not back up before updating.. so that won't help 🙂