ElseIf error, code will not pick if statement

I am trying to build a code that if it finds a specific word in a column it goes to the corresponding column and extracts the data. For some reason my "elseif" for my 3rd loop does not pick up resulting in my code not picking up half the values I need. Can anyone see where I am going wrong?

Sub Summary()

Dim MainLoop As Long
Dim SecondLoop As Long
Dim thirdLoop As Double
Dim Trow As Double
Dim counter As Integer

Dim PSKU As Integer
Dim PDesc As String
Dim PPKG As Integer

Dim CSKU As Long
Dim CDesc As String
Dim CPKG As Long
Dim Cstatus As String

MainLoop = 5
SecondLoop = 0
thirdLoop = 0

counter = 0

Worksheets("final").Activate

    '1
    Do While MainLoop < ActiveSheet.Cells(Rows.Count, "B").End(xlUp).Row
        Worksheets("Final").Activate

        ParentSKU = Range("A" & MainLoop).Value
        ParentDesc = Range("B" & MainLoop).Value

        Worksheets("Summary").Activate

            SumRow = (ActiveSheet.Cells(Rows.Count, "A").End(xlUp).Row) + 2
            Range("A" & SumRow).Value = ParentSKU
            Range("B" & SumRow).Value = ParentDesc
            Range("C" & SumRow).Value = "Parent"

            Worksheets("Final").Activate

                SecondLoop = 0
                '2
                Do While SecondLoop < 20
                Worksheets("Final").Activate
                    '3
                    If Range("H" & (MainLoop + SecondLoop)).Value = Range("I1").Value Or Range("H" & (MainLoop + SecondLoop)).Value = Range("I2").Value Or Range("H" & (MainLoop + SecondLoop)).Value = Range("I3").Value Then

                        CSKU = Range("F" & MainLoop + SecondLoop).Value
                        CDesc = Range("G" & MainLoop + SecondLoop).Value
                        Cstatus = Range("H" & MainLoop + SecondLoop).Value
                        CPKG = Range("I" & MainLoop + SecondLoop).Value

                        Worksheets("Summary").Activate

                             SumRow = (ActiveSheet.Cells(Rows.Count, "A").End(xlUp).Row) + 1
                             Range("A" & SumRow).Value = CSKU
                             Range("B" & SumRow).Value = CDesc
                             Range("C" & SumRow).Value = "Child"
                             Range("D" & SumRow).Value = CPKG

                        Worksheets("Final").Activate
                     '3
                     ElseIf Range("H" & (MainLoop + SecondLoop)).Value = Range("H3").Value Then

                        Worksheets("Final").Activate
                        Find = Range("F" & MainLoop + SecondLoop).Value

                        Trow = 5

                        '4
                        Do While Trow < (ActiveSheet.Cells(Rows.Count, "J").End(xlUp).Row) + 1

                            '5
                            If Range("J" & Trow).Value = Find Then

                                thirdLoop = 0

                                '6
                                Do While thirdLoop < 10

                                    '7
                                    If Range("P" & Trow + thirdLoop).Value <> "" Or Range("P" & Trow + thirdLoop).Value <> 0 Then

                                        CSKU = Range("P" & Trow + thirdLoop).Value
                                        CDesc = Range("Q" & Trow + thirdLoop).Value
                                        Cstatus = Range("R" & Trow + thirdLoop).Value
                                        CPKG = Range("S" & Trow + thirdLoop).Value

                                        Worksheets("Summary").Activate

                                            SumRow = (ActiveSheet.Cells(Rows.Count, "A").End(xlUp).Row) + 1

                                            Range("A" & SumRow).Value = CSKU
                                            Range("B" & SumRow).Value = CDesc
                                            Range("C" & SumRow).Value = "Child"
                                            Range("D" & SumRow).Value = CPKG

                                            Worksheets("Final").Activate


                                    '7
                                    Else

                                    Trow = Trow + 1
                                    '7
                                    End If

                                thirdLoop = thirdLoop + 1

                                '6
                                Loop
                           '5
                           Else

                            Trow = Trow + 1

                           '5
                           End If

                        '4
                        Loop

                    Else
                    '3
                    End If

                SecondLoop = SecondLoop + 1



        '2
        Loop

    MainLoop = MainLoop + 20

    Worksheets("Final").Activate

'1
Loop

End Sub