Interactive Graph with total result - Cant find a solution

Dear Everybody,

I writing out of exhausting looking for a solution. Maybe I am aiming for something unnecessary complex but I was looking to make graph that dynamically changed based on a drop down list. But my plans are being hindered by a specific formula.

The aim would be as follow: The graphs would feed based o formula that shows the total budget of Project A compared to the total of the budget of the portfolio.

I am uploading an example below.

In Sheet1 we have a database of all the projects. Each project has a specific budget and linked to a specific donor. Furthermore, the Donors have other projects.

The aim is to have, in Sheet2, a small, dynamic, summary visually aided by a graph that shows the ratio of the project in the clients portfolio. As seen in Sheet 2, once can chose of the project based on a drop-down list and the other cells change accordingly. The formula I cant quite make out is the ratio formula (Total of Project A compared to the total of the budget of the portfolio) that changes accordingly to the drop-down list. I have tried the following, but it hasn't worked:

=SUM(INDEX(Sheet1!A2:C7,0,MATCH(B6,0,Sheet1!C:C)))


I would deeply appreciate any tip regarding this formula. I have looked up in the forum and haven found a solution. If there is, I apologize for the repetitive thread.

Kind regards,

Javier