Hollie, OMG, I felt your pain a few weeks ago! Im in a small place too about 800 sq ft. Ive had Izzy for almost 2months. (he's 4 months now) The first month or so I had him in his crate and my cousin would check on him mid day. But she started working again so I was back to leaving him all day. I tried going home during lunch but that was too much driving. I live in Detroit, work in Warren...and gas is way to high for that.
When I left him in his crate all day, he did the same thing, pooping and peeing.

My second try was to put him in one of the rooms and section it off but he ended up getting out one day and the other day he climbed over boxes and chewed the heck out of a cardboard box, tore up some of my files! (I jsut moved so i have boxes everywhere) The good thing was he peed and pooped on his pad and was able to eat and drink. So I ended up buying an ex pen. While waiting for it to deliver, I put him in my bedroom with his pad, food, and crate. My room is pretty much puppy proof. He's been doing fine ever since and that has been a couple of weeks. I think he likes it in there because he sleeps in my room in his crate at night. So he's comfortable there. Ive only used the ex pen once when I was home and needed him to be contained.
So after all of that mumble jumble, my advice is to:
1. get an ex pen. They have resonable pens at dig it pet.com. Here is the url of the one I bought:
http://www.digitpet.com/product_grou...FQ8TSQodYk6OQg
I paid like $31 for it. At the pet stores they ranged from $60-$100. That is why I took so long to get one until I found this website.
2. Dont crate him for 8hours + its not good for them. He is confused with all of the changes especially since you were home for so long.
3. If you can put him in a room where there is nothing for him to tear up I would try that. Put shoes, clothes, rugs away.
4. Also before you leave give him a small treat, so that he knows you leaving is not a bad thing. Or the kong idea is a good one. Im going to try that with him too.
5. Turn music or tv on. It doesnt have to be loud, they have supersonic hearing.
Sorry for the long response, I hope this information helps! I understand what you are going through. I hate leaving him all day. Good luck and let us know how hes doing!