What is the best way to combat Peach, Zelda, and Marth?

[CSTL!?]

Every time I play Peach, Zelda, or Marth I get destroyed. Marth's d-tilt is really good and I keep getting walled out with f-airs. I have no idea how to fight Zelda and Peach is just a really bad matchup. I'm spending a lot of time in shield and I know I need to do more OoS options but I just really have no idea how to approach any of these match-ups. I'm definitely going to try and get some videos up of my climbers to try and show you exactly what I'm struggling with. Any advice in these match-ups is super appreciated.

 

[KingKirb]

we have a matchup section with some tips on this subject. check the stickied posts

 

[CSTL!?]

we have a matchup section with some tips on this subject. check the stickied posts

My b.

 

[KingKirb]

My b.

lmaooooooo

 

[DerfMidWest]

much patience and consistency. They are all very slow matchups in which ICs struggle to approach their opponents, which means you have to be on the defensive and look for a solid opening a lot more and being able to capitalize off those openings is incredibly important, since they don't always happen very often.
I also just recommend playing them a lot since you know you are struggling with them, really understand the strengths and limitations of both ICs and the other character and work on ways to max/minimize those.