Help, PS4 save file / profile data wiped & lost some guns!

I joined a random player the other night and after a little while they
had a friend join, about 5 mins later the game froze and a screen from
Sony informed me of some type of fatal error. I closed the game but when
I restarted all my profile data was gone, I was back to lvl 1 with all
my hard won / donated gear gone! Got nearly all my stuff back as I saved
to USB a couple of weeks ago, had saved to cloud more recently but that
was corrupt too.Had to initialise my PS4 an re-install THC, all’s working
fine now but gutted as between my last USB save and the crash I lost 3 OP8
guns that I had been trying to get for months, Boss Bekah with Dahl stock,a
fire Rightsizing Bitch and shock Corporate Bitch!

Anything like this happened to anyone else or know what the cause was
and if possible can someone please help replace the 3 guns I’ve lost?

On a side note, does anyone know why I can’t delete notifications like
friend requests & invite to groups etc? It’s annoying just seeing them
sitting there and not been able to delete!

Thanks