Point 1 - you need to call the forwarding code for all the items in the relevant folder - E.G. See
vba - Outlook VBscript to forward emails in a folder[
^] (but there are literally thousands of examples to find)
Point 2 - you already have the code to add "content" to the email
xStr = "<p>" & "Hi, Your email has been received. Thank you!" & "</p>"
myFwd.HTMLBody = xStr & .HTMLBody