Brad Parscale, who was the campaign manager for Trump through July but was then demoted due mostly it seems to the Tulsa rally debacle and the fact that he appeared to be stuffing his pockets with campaign funds buying expensive cars and properties with it, was picked up by police after his wife called because he was threatening to blow his brains out with one of his guns. He is now in a hospital under observation.

Now, this is another of Trump's criminal cronies and he was still working for the campaign but was apparently upset with getting his hand caught in the cookie jar and being demoted. He's also buds with that scumbag Jared Kushner.

Now, obviously nobody has yet reported why Parscale was trying to kill himself but he has been apparently taking loads of donations to the Trump campaign for his own personal use, a crime, but probably saw that as par for the course in Trumpland and other than complaints from people working inside the campaign, Trump and Kushner have not said anything about it. However, like all people invited into the Trump orbit he probably has multiple criminal endeavors he is involved with and those also could be campaign related. 

So, my take would be he probably has good reason to want to exit this world before he is charged with a crime...which is probably certain to happen if Trump is not reelected.