accumulative summary data in a dynamic table

Hi there folks,
something i can't get my head to solve.
I have this loan repayment table, with different columns of total payment per month, interest per month, remining of the debt and so on.

In another sheet i have this summary of the data per month taken from the original table.
but what i'm trying to do is build is an accumulative table that summarise the first table info for multiple loans.
meaning, if i am getting 1 loan on January and additional loan on June (as in the attached file) i want the loan repayment and interest repayment lines (highlighted) to calculate both of the loans per the number of the payment:
on June for example, the loan i took in June is on the 1st month, but the loan i took in January is on the 6th month, and so on.

i built a summary for each month below the main table to show on which month the loan is at any stage, but to avoid a huge repetitive formula of Vlook-ups, i wish to think of a better solution to calculate the summary.

can someone offer a better, more elegant solution?

the question was asked as well on:
https://www.mrexcel.com/board/thread.../#post-5703048

thank you

Link added by OP Thx