Software to Recover Permanently Deleted Photoslibrary???

If you want to use third-party recovery software, stop using your Mac immediately. Otherwise data that could still be recovered will be deleted.

the Photos Library is a very complex package of files. It is not very likely that recovery software can restore this package and recreate the internal links. You may be able to recover many of the photos, however.

Disk Drill is very good at recovering photos and videos.

Data Recovery is usually quite expensive and the success is uncertain. Use only software, that has a trial version and will let you see what can be recovered before you have to pay.

Don't do that until you have recovered the files first.

Anything you do on your Mac now risks overwriting some or all of the files. So your first priority is to recover whatever photographs can be recovered. When you have that done you can consider how to recreate your filing system and, indeed, contemplate the importance of a working back up.

I would strongly urge that you back up the Library after any session where you make a change - import/edit or organise.

Most Simple Back Up:

Drag the Library from your Pictures Folder to another Disk. This will make a copy on that disk.

Slightly more complex: 

Use an app that will do incremental back ups. This is a very good way to work. The first time you run the back up the app will make a complete copy of the Library. Thereafter it will update the back up with the changes you have made. That makes subsequent back ups much faster. Many of these apps also have scheduling capabilities: So set it up and it will do the back up automatically.

Example of such apps: Chronosync, SuperDuper, Carbon Copy Cloner - but there are many others.