I can't boot my macbook

I read it before going here and it didn't help at all. I updated my MacBook to Mojave (with a self made bootable flash drive installer). Before that i read hardware requirements and my computer was capable of handling it. And everything was good, until I clicked to restart and update software. Like I described, it stops on loading screen and restarts when loading is "complete". Command + R doesn't work (like i have written, it takes me to screen with prohibition sign), Command + Option + R and Command + Shift + R don't work too. MacBook doesn't see my any connected when i boot holding Option. Flash drive with OS install which I made, SD card, just nothing, it sees only it's hard drive. However, when I connect my phone to it, my phone shows me menu (charge only, read files or read photos) when loading screen shows, so it seems like computer reads my device only when loading starts. If it would be usable, when by mac boots it takes me to EFI shell. I don't have any other mac and I want to avoid going to service (and paying inappropriate ammount of money). It's my 2nd computer and I use it to learn something about computers, other OS, just like that.