How do I use i3lock after autologin

Hi everyone!
I wanted to use i3lock both for the first login screen and for all the successive screen. The latter was easy, as it’s just a bindsym, but I’m having lots of problem for the former.
[I’m using zsh]

What I did:

First, I tried to autologin with lightdm but it didn’t work. I also tried with SDDM, but after I successfully set up the autologin and wrote the command to autostart my i3lock bash script [in .xprofile] I entered an hell where I could not escape (but I did, thanks to my trusted usb stick); jokes aside, it was a loop where after I logged in (through i3lock) I had another SDDM login screen, and then another i3lock and so forth…
Thus I used the tty login method, I setup the autologin and the autostart for i3 in .xinitrc. And it works!.. almost. I can’t get the i3lock script to load after i3 is started for the first time and now the unimatrix command I launch through the i3’s config file does nothing (if I start it on a new kitty instance it works just fine though, also it’s not freezed).
I tried to achieve the i3lock autostart by writing in ~/.xinitrc the following:

  1. exec sh home/myUsername/i3/
  2. exec home/myUsername/i3/
  3. source home/myUsername/i3/

What I’d like to do:

When I log in for the first time I’d like to be welcomed by the i3lock screen. And I’d like unimatrix to work as well!