The simplest way is to create either a SharePoint list or an excel. Create a flow. Each time you get a response, update the value by 1.
For each response. check the value to see if its over 100 or whatever configured value, then send the email.
With respect, we do not just write everyone's code for them we are not consultants.
Here are the steps you want if you have a sharepoint list with just the single row
1. When a new response is submitted
2. Get Items
3. Apply to each
--insert get the Value of the rows column
----condition
------if that value is > 100
-------- in the yes side do whatever you want <== in this case disable it via the below post
-------- in the no side do whatever you want
If these suggestions help resolve your issue, Please consider Marking the answer as such and also maybe a like.
Thank you!
Sincerely, Michael Gernaey