Keep in mind that it is not necessary that every problem you face is actually a Windows bug. As a matter of fact, custom configurations, outdated drivers, hardware issues and application conflicts can be the reason behind these issues.
After updating to version 1903 I get only blue screen The freezing system is unusable I have to restart the whole system from the button
Notably, incompatible or corrupted device drivers are generally the major cause of BSOD issues. You should update your drivers before the installation process begins. Moreover, a better approach is to wait for a few weeks until a stable build is available.
Comment down below if you came across any such issues during the installation of May 2019 Update. Let us know how you fixed the issue.