Todomomo

Todo is afraid of Enji scaring Momo off.
Momo is afraid of her parents not approving of him.

Kirimina

Mina is afraid of him getting severely hurt.

Kiri is afraid of letting people die before he can get to them.

Miruhawks

Hawks is afraid of fire
Miruko is afraid of losing her kid and husband. She loves them a lot and would be devastated if she lost them.

Iidamei

Mei is afraid of pushing it too far and losing another arm
Iida is afraid of being forced to retire because of an injury like All Might or his brother.

Kamijirou

Not saying what they think everyone should know before they die.

Dabi x Toga

Dabi is afraid of Enji
Toga is afraid of losing everyone who means something to her, and being left alone.

Nejitama

Nejire is afraid of her quirk not being fast enough and giving the villain a chance to attack her.
Tam tam is afraid of not being good enough.

Mt.Kamui

Yuu is afraid of losing. She never had to face it before because of her quirk but Gigantomachia 👀
Kamui is afraid of Termites.

Ryushot

Ryuko is afraid of losing her kids and husband. She doesn't take heartbreak very easily.

Shinya is afraid of dying in front of his family.

HitoRei

Hitoshi is afraid of being seen as a villain.

Reiko is afraid of being quiet when she really needs to speak up.

Tetsukendou

Tetsutetsu is afraid of being in situations where his quirk doesn't work, or his son being in danger.

Kendou is afraid of losing when there's something on the line. So she's just afraid of losing against a villain really.