I need to acquire this data asap and I cannot seem to find it anywhere. Any help is appreciated!
Your best source for this data will be the County Business Patterns dataset published by the US Census Bureau and available through American Fact Finder. You will need to use the Advanced Search option and filter by dataset (YYYY Business Patterns where YYYY is a given year), NAICS code (62322 is the NAICS code for residential mental health and substance abuse facilities; 62142 is the NAICS code for outpatient mental health and substance abuse facilities), and geography (all counties in Michigan).
I created a quick example for you to examine the data. This is data from the 2014 CBP dataset. Notice that you can switch years along the left hand panel.
Unfortunately, we do not have those years for the County Business Patterns in any of our IPUMS products.