Responses
Only by keeping up what he's been doing till now, showing his genuine feelings without overstepping Yuyang's boundaries. I actually think it's important that Yuyang pull away and get a clear picture of Lihuan's feelings and his own anxieties as two separate things. I think only then can he accept his own feelings, cause he's afraid of the pain his own feelings will cause him if Lihuan does leave, especially for a girl. Yuyang is on fragile grounds anyway, he needs to step away for a bit and clear his head.
This is very sad to witness, YuYang is trapped in his own memories and his worst possible thoughts... its hard to know how LiHuan can fight that.