High Kernel Task slow laggy mac

well I came home, turn my mac on and now it moves really slow.
I checked the activity monitor and it the user% is low but the system% is really high the only process that shows such high cpu is kernel task, i have no idea what to do. I booted up in safe mode and it fixed the problem, but once leaving safe mode it goes back to being really slow with high kernel task. my fans are not on and the computer isn't hot at all.
starting this thread took forever.

Try doing an SMC reset:

Intel-based Macs: Resetting the System Management Controller (SMC)

HTH,

- Nick

Yeah I don't know if i did that correctly im on a macbook air.
and all it did was make the computer not turn on, but then when i decided not to do the SMC and the computer turned on it was running fine no lag and no high kernel.
but then i put the computer to sleep..
and now it's doing it again.

Just did the SMC reset again.
**** works.but its temporary.. so what the **** is wrong with this thing?