Mine updated 2 weeks ago and, so far, I have not noticed any problems. I did think the introductory tips etc. was much better than usual and worked my way through this. I set the cursor so it changes colour. This is a feature I asked Adobe for years ago but nothing happened. The cursor for windows then keeps changing to a contrasting colour so you can easily see it (i.e. Black on White, Red on Green, Blue on Yellow etc.). Once you open an App such as PS, it provides its own cursors which do not have this feature, of course. I used a few other tweaks as well. I have also suffered from MS Office 365 not starting on boot-up about 1/20 times and I have to reboot. So far this has not happened with 1903 but it is early days yet. I know two other who have been updated with no problems.
The only thing that I can suggest is that you quickly revert to the previous version. The effect you have seen was not dissimilar to my wife's PC when it upgraded from 1709 to 1803. I reverted it to 1709 and MS did not attempt to upgraded it again until 1809 which was fine. Her PC has not yet attempted to move to 1903.
Dave