Advice on raising prices

Hey folks, I'm going to increase my prices this week to keep up with the cost of everything. I'm also booked three months out (not a brag, it's been entirely overwhelming fitting people in), and know that that means it's time to raise prices. I've also been straight up told by my colour clients that I am under charging.

I wanted to get some advice on how to go about it. I put up a notice a month ago on my ig and on my square booking site that I will be increasing my prices on new and existing appointments as of feb 1st and have the new prices listed.

Is it morally wrong to increase my prices on existing/prebooked appointments? I'm prebooked so far out that if I only apply the pricing change to new appointments, I'll be struggling financially for the next three months. I'm nervous about making clients feel blindsided incase they didn't see the update.

How would you go about this?