1995 Toyota camry shutdown/startup issues

So Im an idiot and was doing an oil change on my 95 camry v6 SE 1MZ-FE
and I forgot to put my oil filter back on. I had everything completed except
for the filter on and I tried firing up to see if i had oil pressure now keeping
in mind i just replaced the oil pressure switch at the same time. When I
fired up the car my oil pressure light stayed on and the car ran for about 30
sec before I started hearing knocking. well i only let the knocks go about 5-
10 times before i shut down the car and then noticed i forgot to put the oil
filter back on and i lost about 2 quarts of oil. I put the filter back on and put
more oil in the car but when i went to start the car up it will not fire up. it
sounds like it is trying to turn over but wont. ANy ideas of what I may have
done to the engine or if there is a safety in place that wont allow the engine
to fire back up or if i have to unhook the battery for a while to do a total
reset. Any thoughts/ideas would be greatly appreciated.