caninemiss wrote: …what happend? 
Of course, no one here was there with you, so we can't tell you what happened. 
Can someone tell me easy understandable for a "non technical person" to get my  organized ( albums back ( past 16 years )all of ehich have been on my latest 2023 lap top 
A. I would suggest that you just restore from your Time Machine backup:
Time Machine Restores a Photos Library - Apple Community
B. If you don't use Time Machine, then you should restore from whatever backup system you use. 
C. If you can't do that, it sounds like you could use Smart Albums to do this organizing for you. I don't know what you alphabetized, but you could use something like this:

to collect similar pictures into albums. Or you can collect by date. You can use the Map view to collect pictures by location. Here I've put all the pictures from London in the Map view into an album called London, and then searched for a range of dates:

D. Are you sure you are looking at the same Library? Sometimes a sudden change in a a Library is really from switching to a different one. You should open the Library Chooser to check. Close Photos, and then option-click on the Photos icon to get this dialog:

You can see which is your System Library, what you used last, and see if you have any other Libraries that Photos knows about.
By the way, using iCloud isn't a reliable backup for blunders, since it just copies those, too. iCloud Photos is for sharing pictures with other devices like iPhones. Time Machine is probably the easiest and best backup. I use that, and I make copies of my Library to external drives, both A and B above.