Engine knocking BAD, no power to front wheel drive or reverse.

Shifting gears on the car a slight shutter was happening,
thought I needed to change the transmission fluid sooner
than 'recommended'. Went to go to work, picking up a
delivery around the corner, left the car running while I ran
into the store. Putting it in gear, reverse almost went
forward. Drive and low gear nothing, no power, just
increased grinding & engine knocking. Car is currently
disabled, no check engine light, afraid to start it causing
more damage. Was working fine two days ago (drove it 2
hours round trip, no issues), but now it won't run. Someone
in my housing complex do something to my car while not
in use? Power train? Transmission? Power transfer?
Misaligned belt? Lemon law report to Nissan consumer
affairs as this seems to be an on going issue with their cvt
engine models. Again, nothing wrong last time I used the
vehicle to the engine clunking, knocking & no transfer
power in any gear. Lights out where you shift from (p, r, N,
d, L) only work occasionally if you tap on center console.
Putting it in gear increases grinding & knocking, with zero
power. Worst if you give it gas to the point it feels like the
engine is going to fall out. Fresh oil change, wheels,
alignment, rear brakes. Did they miss something doing the
oil change, (Oil looks fine and at correct level), knock a
vacuum seal loose? Really feel like someone sabotaged
my car in my parking lot. Thoughts on what's wrong?
Thanks all!