a while ago i did a bunch of mental health tests and apparently i have schizophrenia, ADHD, depression and social anxiety. is it normal to have that many all at once or do these things usually come in groups?

Preliminary diagnosis usually is more then one diagnosis. (Such as depression and anxiety) As the doctor sees you more and more sometimes your diagnosis will change because mental health issues tend to become more prominent as they get to know your unique situation better. In other words a person may come in with symptoms of depression one month, be diagnosed with depression. Then the next month come in for the session in a manic state where the doctor now sees you may be bipolar instead of just depressed. Of course it does take more time then what I summed it up as but you get the point.