It will be easiest to perform a clean install of macOS by first erasing the whole physical drive and reinstalling macOS before restoring from a backup. I hope you made a backup before messing with the partitions since modifying partitions is a major undertaking with potentially disastrous consequences.
While it may be possible to "fix" the issue without resorting to the clean install, there is only one forum contributor that I am aware of that even has the knowledge to assist you, but I have not seem him post on here for several weeks (plus he needs to see your post which is one among thousands -- meaning it is unlikely he will see the your post).
If you don't have a backup, then you may be able to install macOS to an external USB drive so that you can boot the Mac from the external drive so that you can attempt to recover your data perhaps with a data recover program such as Data Rescue. If you have a 2018+ Mac with the T2 security chip, then booting to an external drive is impossible unless you modified system security settings to allow booting from USB (this may not be possible now, but you could still try). You can attempt to boot into Internet Recovery Mode using Command + Option + R to hopefully access the most recent version of the online macOS installer (otherwise you will need to upgrade macOS on the external drive in order to be able to access the internal drive). Just make sure when "installing macOS" that you select the external drive as the destination drive, otherwise you will overwrite and destroy the files you are hoping to rescue!
Another option would be to contact a professional data recovery service such as Drive Savers or Ontrack. Both vendors provide free estimates and both are recommended by Apple and other OEMs.
You should always have frequent and regular backups. It is impossible to recover accidentally deleted data from an SSD after the Trash has been emptied plus an SSD can fail at any time without any warning signs. With USB-C Macs, it is very difficult to impossible to recover data if the Logic Board is not functional since the SSDs are soldered to the Logic Board and with 2018+ Macs the data is also hardware encrypted for extra security.
