HELP PLEASE Shelf fell off wall in 2019 320 U

ColleenD2

Any idea the best way to get this back up there? We aren't handy but I follow instructions well.

We have a 2019 320 U Boondock edge. It came with the shelves above the windows and the nets on them. There really was nothing weighty in there. I think what's happened is the glue has failed.  I can still see some little nails sticking out. I was afraid to unscrew the net screws so I just cut it. I don't really use that net anyway. Oh GodCurrently enjoying a little duct tape fix since this happened on the road. We've been storing at home with a cover but no garage or carport and we've had a horrendously hot summer here in St. Louis, Missouri. The part with the switches has been loose for a while but I glued it last year with wood glue and it seemed to be holding until this year. 

Is there a cabinet glue that can withstand severe temperatures? I hate to screw or nail into it.

* Moderator, I wasn't sure where to post this so feel free to move it.