hi,
The problems with your 5V reg are:
1. You had a 6Vpk AC input to the bridge.
2. The 1N4148 are only signal diodes
3. Incorrect and missing capacitors.
4. Part of the bridge shorted out via the 'ground's
LTSpice is only a simulator, you have to design the circuit correctly for it to give you the required performance.
Run this edited version of your circuit.
BTW: in your TRAN, you have a Run time of 1 Sec set, with a STEP interval of 5 Secs!!!
I did tell you about this previously.