Amortization Help

Hi all, I am hoping that someone can help me out. I am a bit of a noob when it comes to Power BI but because I have touched it once or twice, I was voluntold for this project.

I am creating a financially focused project planning dashboard intended to plan for next year’s initiatives. The area I am stuck on is year-over-year rollups of amortized payments.  The objective is to capture what the cost will be within a fiscal year. For example, if a project starts in June of this year, costs $1000, and has a 1-year amortization schedule then my cards should read $500 for this year and $500 for next. Below is a screenshot of the fields that the department heads will use to input their data.

What I need assistance with at this point is:

1. I have a project start date earlier in the form. I was trying to use DATEADD to dynamically determine the end date of the amortization schedule, but I cannot get it to accept the value from the field entry.
2. I assume that a combination of this blog How to divide/distribute values between start date... - Microsoft Power BI Community and slicers will address the remainder of my issues but if you have any suggestions I am open to them