Any tips on how to keep time when playing periphery songs on guitar?

I know chunks of songs but then I get discouraged when I try to piece them together or play them at speed.

I practice to guitar pro with the metronome set and my muscle memory gets good at learning the songs but playing the riffs to a metronome alone is extremely daunting to me.

I tried to play the intro of graceless yesterday to a metronome alone since I could play it up to speed with guitar pro, but I failed miserably.

Any tips?