absolutely heart-breaking!! all that great work and gets spoiled by stupid design. really, what engineer in his right mind says yes... let us carry a dynamic load through a bolt that is TTY and also removed with relative frequency. The block should have a spindle cast into it that carries the load, and a bolt should only hold the bearing tight to the spindle. The same way the engine shouldn't hang off bolts either, esp not bolts threaded into aluminum.
I hope your engine is ok and you can get the car back together, actually enjoy it a little while.