How do I automate monthly payment reminders and receipts from Google Sheets using Zapier?

Good morning, 

I would like to automate my child support reminders to my ex. I have a Google Sheet that has all of the data that I would like to connect to Gmail. 

Here is what I would love to automate: 

1. Send a monthly email reminder email with mail merge fields that read from the Google Sheet for the last payment amount and date received, what is due this month, and the remaining balance owed. 
2. If I have not changed the “Payment Received” cell in my google sheets, I would like a reminder email to be sent with the same information. 
3. Once I do receive payment and I make a change to that cell, I would like a receipt of that payment automatically emailed, including mail merge fields.