macOS 10.14.5 version

I had some problems installing a new available update macOS 10.14.5 to my MacBook Air. As usual I installed update through System Preferences -> Software Update, dowloaded it, restarted my computer then shut it down after I'd finished with my work. The following day the problem appeared while I was unsuccessfully trying to turn on my computer, there was only black screen with apple logo on it, without any bar which shows you the remaining time etc. I left the computer for probably 40 minutes hoping for the best and after realising that it wasn't reacting at all, I restarting it using cmd+R with holding On/Off button. It helped for that day even though it was necessary to restore everything from Time machine. Later that day Macbook automatically installed the new update and automatically restarted, but when I tried to turn in on it was not reacting at all (there was no sound, no pictures, logos and so on). I tried all advices recommended on Apple support, but it didn't help at all. At the end I had nothing to do than to go for the Apple service and left my computer for repair. It costed me pretty much, because it was told me that they had reinstalled the operational system completely and it is not recommended for me to update for the following version. Now I have restored everything again from the Time machine, but the computer is showing me the notice that it had installed a new update (this 10.14.5 version) and needs to be restarted, even though I had turned off this automatically downloading and installation option off. I would like to ask you what I have to do now, because it really annoys me that I do not know how to get rid of this problem with this update version and also do not want to go to service office and pay for repair again. I will appreciate it if you give some recommendations what will be better to do in this case or fix the issue.

Thank you!