I have 96 rodeo, auto, 205k miles, runs beautifully. when I pulled the crossmember to change the trans filter,(first time for me with this truck) the bolts that go into the frame all broke

it turns out that the welds on the nuts broke also.

Any ideas on what would be the easiest way to solve this problem? Is the only way to fix this cutting off the mounting boxes and remanufacturing new ones? does anyone make these boxes already?
This is my only transportation, and now I can't even take the jack out from under it. Any help is greatly appreciated. pics will be up in a couple of hours.