He's scared Doha will reject him the moment he's emotionally vulnerable, because that's been the pattern in their relationship
Joon is constantly giving and making space in their relationship, so much space that there isn't room for his emotional needs to be met. Doha is willing to listen and is attentive NOW and is trying to make that space for Joon now, but he hasn't been up until this point (something even Doha is realizing)
So no, I don't think it's fair to expect Joon to flip a switch and open himself up to potentially way more hurt just because we, the audience know that Doha is trying to be better.
If you don't express your emotional needs, they won't be met, but you won't be risking the pain of someone you love actively ignoring or refusing to give you what you need when you ask directly.
It's not healthy, but it's a pattern that Doha has fed into (tho he didn't realize it) and it's not something that's easy to fix
Can they just resolve those internal conflicts and communicate like stop fucking n think it’s the solution. Especially joon! Get a grief bro yk Doha loves you and wants you to open up to him. What r you so scared of dude