Draco really doesn't understand Harry at all. For one thing, he's had how much experience of the fact that Harry doesn't surrender completely, and yet he thinks Harry is surrendering completely on all matters because he's behaving a bit better on one thing. Clueless, really.

Draco is mentally healthier in at least this way, yes. He doesn't tend to waste too much time angsting about whether it was his fault that his past relationships ended, whereas Harry tends to assume it is and internalize the guilt.