exactly my thoughts ,,It was fine one minute, then all of a sudden no compression on all cylinders?
You might be lucky and the timing belt jumped severely but didnt bend any valves, or it did and you bent valves.
Verify mechanical timing, pull upper timing cover and see if stuff still lines up. If your out of time, retime it, then do another compression test.
If you still have low comp after rechecking timing, do a leakdown test. Again, verify everything is mechanically in time BEFORE doing a leakdown. No sense in doing a leakdown if your severely out of time.
Do a leakdown test on any cylinder TDC compression, see where air is leaking out.
especially since all cylinders are low..
or maybe a whack gauge ..
also check the main relay ....when the key is turned on does the fuel pump prime?