Adding values in multiple arrays

[Stclements1]

Loan Sheet.xlsx
	A	B	C	D	E	F	G	H	I	J	K	L	M	N	O	P	Q	R
1	Month	Capital Input	Fund Value	% Return on Capital	Fund Plus Interest	Loan Period	Interest Rate	Interest Payment	Capital Payment	Total Monthly Interest Payments	Total Monthly Capital Payments	Fund Payment		Fund Balance
2				0,04
3	1	10000	10 000,00	400,00	10 400,00	1	0,00700	70,00				0,00		10 330,00				Term
4	2		10 330,00	413,20	10 743,20			0				0,00		10 743,20				1
5	3	80000	90 743,20	3 629,73	94 372,93	2	0,00975	780,00	1 000,00			0,00		92 592,93				2
6	4		92 592,93	3 703,72	96 296,65			0				0,00		96 296,65				3
7	5	15000	111 296,65	4 451,87	115 748,51	3	0,00750	112,50	8 000,00			0,00		107 636,01				Repayments
8	6		107 636,01	4 305,44	111 941,45	2		0				0,00		111 941,45				10
9	7	12000	123 941,45	4 957,66	128 899,11	2	0,00725	87,00	1 500,00			0,00		127 312,11				22
10	8		127 312,11	5 092,48	132 404,59			0				0,00		132 404,59				34
11	9		132 404,59	5 296,18	137 700,78			0	1 200,00			0,00		136 500,78
12	10	10000	146 500,78	5 860,03	152 360,81	3	0,00750	75,00				0,00		152 285,81				%
13	11		152 285,81	6 091,43	158 377,24			0				0,00		158 377,24				0,70%
14	12		158 377,24	6 335,09	164 712,33			0	1 000,00			0,00		163 712,33				0,8250%
15	13	13000	176 712,33	7 068,49	183 780,82	1	0,00700	91,00				0,00		183 689,82				0,95%
16	14		183 689,82	7 347,59	191 037,42			0				0,00		191 037,42
17	15		191 037,42	7 641,50	198 678,91			0	1 300,00			0,00		197 378,91				%
18	16	40000	237 378,91	9 495,16	246 874,07	1	0,00825	330,00				0,00		246 544,07				0,00%
19	17		246 544,07	9 861,76	256 405,83			0				0,00		256 405,83				0,0250%
20	18		256 405,83	10 256,23	266 662,07			0	4 000,00			0,00		262 662,07				0,050%
21	19	25000	287 662,07	11 506,48	299 168,55	3	0,00750	187,50				0,00		298 981,05
22	20		298 981,05	11 959,24	310 940,29			0				0,00		310 940,29				Value
23	21		310 940,29	12 437,61	323 377,90			0	2 500,00			0,00		320 877,90				0
24	22	18000	338 877,90	13 555,12	352 433,02	2	0,00725	130,50				0,00		352 302,52				30000
25	23		352 302,52	14 092,10	366 394,62			0,0				0,00		366 394,62				75000
26	24	15000	381 394,62	15 255,78	396 650,40	3	0,00750	112,50	1 800,00			0,00		394 737,90
27																		0,01
28		238000																0,02
29																		0,03
30																		0,04
31																		0,05
32																		0,06
33																		0,07
34																		0,08
35																		0,09
36																		0,1
37
38
Sheet2

Cell Formulas
Range	Formula
C3	C3	=B3
D3:D26	D3	=C3*$D$2
E3:E26	E3	=C3+D3
C4:C26	C4	=B4+N3
I5,I26,I23,I20,I17,I14,I11,I9,I7	I5	=B3/INDEX($R$7:$R$9,MATCH($F$3,$R$3:$R$5))
G3	G3	=INDEX($R$13:$R$15,MATCH(B3,$R$23:$R$25,1))+INDEX($R$18:$R$20,MATCH(F3,$R$4:$R$6,1))
G4:G7,G26,G24,G21,G18,G15,G12,G9	G4	=IFERROR(INDEX($R$13:$R$15,MATCH(B4,$R$23:$R$25,1))+INDEX($R$18:$R$20,MATCH(F4,$R$4:$R$6,1)),"")
H3	H3	=IFERROR((B3*G3),"")
H4:H26	H4	=IFERROR((B4*G4),"0")
N3:N26	N3	=E3-(H3+I3+L3)
B28	B28	=SUM(B3:B27)

Cells with Data Validation
Cell	Allow	Criteria
F3:F26	List	=$R$4:$R$6
D2	List	=$R$27:$R$36

In column B I have a list of values which represents Loans
In Column F I have the term (years) of each loan
In Column G I have the interest rate for each loan which is determined by the value of the loan and the term of the loan (details in column R)
In column I is the capital payments of each loan this is determined by the term of the loan and the first payments are made on the third month of the loan and every month thereafter for the duration of the loan. Example 1 = 10 payments, 2 =22 payments and 3 =34 payments. These are incorrect in this column as the first payments should be on the 3 month after the loan commences,
What I am attempting to evaluate in columns J and K is the ongoing accumulated monthly interest payments and capital payments which means adding each one as it falls due and then as the term of the loan is completed based on its corresponding value in column F so there are no further payments from that specific loan calculated.
Hopefully I have given enough clarity but will happily provide further data if needed.