Is this homebrew Dreams&Sleep domain balanced compared to the official domains?

I am making a compendium of homebrew Cleric subclasses, spells and feats, but I want to make sure it is actually balanced and there are no glaring loopholes or broken combos with existing feats, spells, and subclasses before I release it. Is this homebrew Dreams&Sleep Domain balanced compared to the other cleric subclasses?

Dream and Sleep Domain

Dreaming and sleeping might seem like the last thing to do in battle, but by infiltrating dreams one can undermine an enemies psyche, and by controlling their sleep, you can cause them to enter a slumber during the heat of combat. Gods of sleep and dreaming include Diirinka, Sehanine Moonbow, Niorun, Hypnos, and Morpheus.

Domain Spells

1st Sleep, Dissonant Whispers
3rd Gentle Repose (R), Mind Spike
5th Catnap, Enemies Abound
7th Phantasmal Killer, Shadow of Moil
9th Dream, Synaptic Static

Aura of Mental Protection

As reaction, when a creature within 30 feet of you fails a wisdom, charisma, or intelligence saving throw, you can make them reroll the saving throw and take the higher result. You can use this a number of times equal to your wisdom modifier, regaining uses on a short rest.

Sleep Optimization

For you and creatures within 30 feet of you, a long rest only requires 7 hours instead of 8. This decreases to 6 hours when you reach 19th level.

Channel Divinity: Psychic Reconnoitre

At 2nd level, as an action, you can touch an unconscious or sleeping creature and use your channel divinity to affect its dreams to tear down its mental defenses. For 8 hours after the creature wakes up, they will have disadvantage on the first wisdom saving throw, the first intelligence saving throw, and the first charisma saving throw they make. They can get rid of this effect by taking a short or long rest.

Channel Divinity: Inception

At 6th level, as an action, you can target a creature within 60 feet of your who has taken psychic damage from a spell you cast in the last minute or has failed a saving throw against a spell of the enchantment or illusion school you cast in the last minute. You use your channel divinity to create layers and layers of dreams within their mind. That creature must make a wisdom saving throw or take 4d12 psychic damage and be stunned for the next round. The creature also ages by 1d4 years. The damage increases to 8d12 at level 15. A creature who fails a saving throw against your Inception once can never be aged by it again.

Psychic Spellcasting:

Starting at 8th level, whenever you deal damage with a cleric cantrip, you deal additional psychic damage equal to your wisdom modifier.

Mental Fortress:

At 17th level, you are always under the effects of a Mind Blank spell.