Assign value from userorm textbox to variable?

Sub SplitSystemNewSheet()
    Dim wsAll As Worksheet
    Dim wsCrit As Worksheet
    Dim wsNew As Worksheet
    Dim LastRow As Long
    Dim LastRowCrit As Long
    Dim i As Long
    Dim Message1, Message2, Message3, Title, Default1, Default2, _
        Default3

    'turn off screen updating
    Application.ScreenUpdating = False

    'select the first worksheet with the data
    Set wsAll = Worksheets(1)

    LastRow = wsAll.Range("A" & Rows.Count).End(xlUp).Row
    
    'show the form
    Load UserForm1
    UserForm1.Show

    'use col z for the formula to extract the required characters
    With wsAll.Range("Z1")
        .Value = "ID"
        .Offset(1).Resize(LastRow - 1).Value = "=MID(" & MyVal1 & "2," & MyVal2 & "," & MyVal3 & ")"
    End With

    'add sheet for the criteria
    Set wsCrit = Worksheets.Add

    'column y has the criteria eg ID
    wsAll.Range("Z1:Z" & LastRow).AdvancedFilter Action:=xlFilterCopy, CopyToRange:=wsCrit.Range("A1"), Unique:=True

    LastRowCrit = wsCrit.Range("A" & Rows.Count).End(xlUp).Row
    For i = 2 To LastRowCrit

        'add new sheet for each system
        Set wsNew = Worksheets.Add(After:=Worksheets(Worksheets.Count))
        wsNew.Name = wsCrit.Range("A2")
        wsAll.Rows("1:" & LastRow).AdvancedFilter Action:=xlFilterCopy, CriteriaRange:=wsCrit.Range("A1:A2"), _
                                                  CopyToRange:=wsNew.Range("A1"), Unique:=False
        wsNew.Cells.WrapText = False
        wsNew.Cells.EntireColumn.AutoFit
        wsNew.Range("A1").Select
        wsCrit.Rows(2).Delete
        wsNew.Range("Y:Y").Clear

    Next i

    'disable confirm sheet delete dialogue and delete sheets
    Application.DisplayAlerts = False
    wsCrit.Delete
    wsAll.Delete
    Application.DisplayAlerts = True

    'turn on screen updating
    Application.ScreenUpdating = True

    'clear memory
    Set wsCrit = Nothing

End Sub

Sub CommandButton1_Click()

    MyVal1 = Me.TextBox1.Value
    MyVal2 = Me.TextBox2.Value
    MyVal3 = Me.TextBox3.Value

    Unload UserForm1

End Sub

'show the form
    Load UserForm1
    UserForm1.Show
    
    'assign values from userform
    MyVal1 = UserForm1.TextBox1.Value
    MyVal2 = UserForm1.TextBox2.Value
    MyVal3 = UserForm1.TextBox3.Value

Sub CommandButton1_Click()

    Me.Hide

End Sub