I have a similar problem, but not near as bad as yours. Door was difficult to open/close as it hit the frame at the outside bottom of the door. I played around with the top part of the enclosure, trying to see if I could maybe loosen things up and pull it back plumb, but there doesn't seem to be any "adjustment" ability. So here's what I did:
The door's pivot point is a pin that goes down into the frame. There is a piece of plastic that it goes through; it supports the door and the door turns on it. You should be able to raise the door, sliding the pin up through its hole, about 1/4' or so. I got some 0.040" and 0.020" plastic sheet (hobby shops sell it) and cut a "square C" shaped piece out of both sizes of plastic. This needs to be "C" shaped because it needs to encircle the pin. I then lifted both the door and the existing piece of plastic that it rode on and slid the "C" shaped pieces under the existing plastic piece. This raised my door 0.060" and allowed the door to close.
The door sweep doesn't do much anymore except at the far end of the door, but as discussed in another thread, it's not a big deal.
I've added a pic that maybe helps. You're basically shimming up the door support. Use enough "C" pieces of whatever sizes you need and/or can get under the existing support. Also, you may end up having to cut some of one of the "tabs" of the "C" off if you can't get it all the way around the pin.
1988 Coleman Sequoia - popup (1987-2007)
2012 Roo19 - hybid (2012-2015)
2016 Mini Lite 2503S - tt (2015 - ???)
2011 Traverse LT, 3.6L, FWD
2009 Silverado Ext Cab, 5.3L, 4x4, 3.73
2016 Silverado 2500HD Dbl Cab, 6.0L 4x4, 4.10