So quick update, after the call I had with someone earlier, I was able to finally figure out my problem. It turns out that I had the SQL function wrong that I started with and also some of my relationships/Links between tables were not correct (newbie errors basically) and we changed it to this and it fixed it perfectly:
Code:
Private Sub cmdAdd_Click()
Dim strSQL As String
Dim lngID As Long
Dim strProductCode As String
Dim strAmtInStock As String
lngID = Me.ID
strProductCode = Me.Product_Code
strAmtInStock = Me.Amt_In_Stock
If Me.Dirty Then Me.Dirty = False
strSQL = "INSERT INTO ItemCart(ID, [Product Code], [Amt In Stock]) " & vbCrLf _
& "Values (" & lngID & ", '" & strProductCode & "', " & strAmtInStock & ");"
Debug.Print strSQL
CurrentDb.Execute strSQL, dbFailOnError
MsgBox "Item Added", vbInformation
On Error GoTo 0
Exit Sub
cmdAdd_Click_Error:
MsgBox "Error " & Err.Number & " (" & Err.Description & ") in procedure cmdAdd_Click, line " & Erl & "."
End Sub
We made some other tweaks to it, redid my form structure, but this code is what fixed the problem I had in case someone is googling and searching for a similar issue and wanted to see how this was resolved. I really appreciate everyone's help on this! I had been stuck for over a week and was starting to lose my mind lol.