Whoa! What an interesting dream. I haven't had a chance to read the responses to this post so I'm just going to throw in my interpretation:
The Zombies seem to denote an ending (death) and the refusal for some idea, situation or fear that has run it's course (in your life maybe) but for some reason you have not fully let go. So it's still around although it really should have no impact
This is not for the lack of trying however. You're in the woods-which could mean the wilderness--for some reason it could be a self imposed exile---okay, so I see a biblical reference here [Satan tempting Christ in the wilderness--it's just a thought])--you know sort of take the gloves off and eradicate the mess.
You're controlling the situation which is why the Zombies are coming out because you want to settle this once and for all--it's actually a good thing. Decapitating them ala a horror movie scenario is poetic justice. Seems as though you are decapitating the mess out of your life. Sometimes it's overwhelming which why some of them kept coming back (finding their heads and reattaching them). Kicking/Punting them into the woods is a good idea but you run the risk of them emerging again at a later date (they should be kicked into a sea of forgetfulness never to return).....So the end result is............your answer all along:
The tying of the shopping bags (while funny) is an interesting sign. Tie up the loose ends of whatever the situation is and you'll get rid of the Zombies--they haven't a clue as to how to do it. This means you're going to win.