/dev/nvme0n1p5 partition full

My partition /dev/nvme0n1p5 is full and I can't boot anymore my ubuntu 20.04. I succeeded to launch a live USB and boot repair told me : "The nvme0n1p5 (Ubuntu 20.04.5 LTS) partition is nearly full. This can prevent to start it. Please use the file browser that just opened to delete unused files (or transfer them to another disk). Close this window when you have finished." I already tried the common commands like clean, autoclean and autoremove but nothing changed. I also checked the kernels and snaps but I have nothing useless. I really need a solution. This is my df -h : here

Thank you in advance

from the livecd, autoclean has no effect. it tries to autoclean the running system, ie the livecd one. You need to remove files from your 29Gb FS. What can be safely removed are logfiles, journal files, and apt cache archives. Of course, if you don't have much of these, you won't gain enough space. In the livecd, with your drive mounted as /mnt/boot-sav/nvme0n1p5 as shown on the image, do the following:

1. Become root

   sudo -i
   

2. Once you get the root prompt do this:

   rm -f /mnt/boot-sav/nvme0n1p5/var/cache/apt/archives/*
   journalctl -D /mnt/boot-sav/nvme0n1p5/var/log/journal --vacuum-time=1d
   find /mnt/boot-sav/nvme0n1p5/var/log -name '*z' -delete
   for file in /mnt/boot-sav/nvme0n1p5/var/log/* /mnt/boot-sav/nvme0n1p5/var/log/*/* ; do test -f "$file" && : > "$file" ; done
   exit # this will exit root shell
   df -h | grep nvme0n1p5
   

If you're lucky, you should be able to boot your ubuntu. once booted try to remove things, or add more space.