This sounds as though you want to examine 5 seconds operation of a circuit running at 1 GHz. It's an example of mixing micro and macro events. It becomes mismatched and unwieldy in simulation. (It is not a problem with real electronics, of course.)
Consider trying a longer timestep.
Also try a slower switching rate in your simulated circuit. You don't have to do the same in your real circuit. The aim is to examine approximate behavior, without having to wait 30 hours.
Set an initial charge on capacitors, so they don't start from zero.