What is your current skill level?  What songs are you playing along with?

I think most of this issue comes down to familiarity & repetition.  You can follow the singer or guitar part because you know what to expect, you know what you hearing, what it is supposed to sound like & when it happens.  You probably need to acclimate yourself to what a piece of music sounds like without those guiding cues. 

Some of that is just being confident in mapping out the song in your mind ahead of time so you have a clear idea of what you need to play and when you need to play it.

Some of that is just repetition.  You need to play the parts until they become second nature.  Then you can focus on big picture stuff like, where you are in song.  This is the verse.  Four bars until the pre-chorus.  Now I'm in the pre-chorus.  Here's the chorus.  Get ready to return to the verse.  But that can't happen until you are completely confident in your skills to play the parts without having to focus on every little motion or chord change.  

Turn on the metronome & strum a chord to every beat.  Can you do that?  It's a great place to start.

Then try to play a simple chord progression to just the click.  Each chord for 1 bar, then end on A.

A / D / A / E  / A

Can you do that?

How about each chord for 2 bars?

A / A / D / D / A / A / E / E / A

Let me know if that helps & how it goes!