I have a weird problem with my new computer.

I have built a pc using new pieces, and a friend’s GPU. After installing successfully ubuntu 18.04.2 LTS on a 480GB SSD (with a UEFI partition), it worked fine for a few weeks. But two days ago, I had to shut down my computer after a freeze, and I pressed the physical button for 5 seconds (I know I shouldn’t have done that, should have used SysRq + s e i u b instead), but now, I can’t boot anymore. I can access GRUB, but both kernels 4.18.0-18-generic and 4.18.0-17-generic give this output (cf. image):

end Kernel panic – not syncing: Attempting to kill init! exitcode=0x00000004

But I was able to use my system from a live session by following this method but when I am using simple linux commands like “apt”, “apt-get”, “wget”, "vim", and others, I immediately get this error : Segmentation fault (core dumped) .

I removed the last things I installed by using dpkg, but I have noticed a strange thing : the /var*/*lib/dpkg/status file is corrupt ! There are dozens of lines containing unreadable characters. Maybe some other system files are corrupt and as a result some commands are unusable. This may have appeared after the forced shutdown...

One more thing : the diks utility from the live-session says “Disk is OK, 370 bad sectors”, but as I’ve said, my SSD is brand new.

dmesg gives this output when I'm typing apt or vim :

[ 2018.144843] apt[5272]: segfault at 0 ip 00007f4681623940 sp 00007ffe60d5d308 error 6 in libapt-private.so.0.0.0[7f46815f0000+60000] [ 2018.144853] Code: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <00> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

I think the only way to make it work is to reinstall Ubuntu, but I would like to know if there is another way to recover it, and why has this issue appeared after a forced shutdown.

This is the second time I'm getting problems after a forced shutdown, the first time was just after the first installation, and I had to install ubuntu one more time.

What I’ve done so far :

ran fsck from a live session (had to fix some errors) managed (I don't know how) to boot in a command-line session, but not in a graphic session -> same Segmentation faults with basic commands

Here’s my hardware (I bought every piece few weeks ago, except the GPU) :

CPU : Intel core i5 8400

Motherboard : MSI Z390-A PRO

BIOS : 7B98v15

PSU : be quiet! System Power 9 400W

SSD : Kingston UV500 (480g, M.2 Connector 2280)

GPU : Gigabyte RX 460 4gb OC

Monitor : LG 24mp58vq

RAM : 2x8g Corsair Vengence 3000mHz (running at 2933) (I had to change it two weeks ago because my pc wouldn't turn on)

System : Ubuntu 18.04.2 LTS

Thank you

EDIT : after reinstalling libapt-pkg using dpkg and replacing the dpkg status file by an older copy of it, apt update works again but gives the error

E: Method http has died unexpectedly! E: Sub-process http received a segmentation fault. E: Method /usr/lib/apt/methods/http did not start correctly

Well I guess some files are still corrupt