need opinions please

[vortecmax55]

i have a 2008 silverado vortecmax 6.0. i was traveling 2 hours north the other day. my oil pressure low shut off truck immediatley code alarmed out. stopped got oil. then it was ok. my oil pressure guage is usually at 40psi. after that occured it jumps between 20-30psi. got home. ran around a bit. now it all of a sudden has like no power. rough idle. and seems like it will shut off if i came to a stop. any ideas?

 

[zora]

How much oil did you have to add?
What viscosity oil did you use?
Have you rechecked oil level when cold?
Do you have a check engine light on?
You usually have 40 PSI at idle?