Update not working

This update has made using features a lot more difficult. Using the brush tool on different layers used to be seamless, but now requires creative work arounds and playing with object flatness in order to add a design on top. Once that is done, it is challenging to figure out how to go back to selecting objects again. I am having to stop work and google these how to's constantly when I used to be able to do so easily. This has become incredibly frustrating.