I accidentally deleted the catalog that I use for LR 6. Unfortunately, I have not been good about backing up my catalog (lesson learned).
I was able to migrate an old catalog from an older version of LR but now cannot see pictures from the last two years in LR. I know that they are still on my hard drive as I can see them in the folder.
Any suggestions to get all my photos along with edits that I have made into one catalog?
Why do you "THINK" you DELETED your LR6/CC catalog?
The only way to do that is from a File Manager program like Window/File Explorer or Mac OS X Finder. You can't do that from within Lightroom.
More than likely you some how opened an older Catalog and that then became the Default catalog to open every time you start Lightroom.
Use a File Search feature or an add-on program to search your drive for *.lrcat (That is LR not ir). If you find one that is named Lightroom Catalog.lrcat that is the LR6/CC catalog. Make a Note of where it is located, IE Write down the Path to it, then open LR and select File>Open Catalog and Browse to that path and open that file.