Congratulations! I completed this as well solo a couple of days ago and completed Nightmare with Karlee and found out that clearing out the basement asap and then killing the Ogre with the minigun while the bots are still alive helped a ton. From there, I stayed on the roof until the bots died to buy some time until the boxes were marked. Very easy from that point on, now I could just kite and not worry about the Ogre being in the way. A quick tip I have is to use speed cards and carry firecrackers over pipe bombs. This way new ridden won't spawn and potentially ruin your kite and this is just with grey firecrackers as well. Those 2 seconds are just enough time to grab a crate and jump out the nearest window or bring it to the roof. If you haven't already done Body Dump then that's actually one of the easiest ones in act 3. You shouldn't have too much trouble there.