I don't think that trust equals to attachment or that there is necessarily a causal link between the two. I trust many people, many of my colleagues for example, or a doctor I have been seeing for a while. I may or may not like them (even know them very well) on a more personal level but I trust that they are able to fulfill their role in our specific relationship in a satisfying way. I get attached to a very few people, in comparison. So I don't think attachment is necessary for trust, maybe more the other way around, but I do not believe attachment is needed for therapy (or any other kind of help) to be useful. The way I see it: many people perceive their Ts in a much more holistic way than what their roles are, all the projections, transference, whatever we call it can lead to that. And that can turn out as painful because, sooner or later, clients will need to face the reality that the T is not many of those things (and it does not help that many Ts/modalities encourage those unrealistic perceptions/feelings). So, I think it might not be a bad strategy sometimes to control the feelings of attachment if possible (push it away when it turns excessive or overly unrealistic, when it interferes with effective therapy) without rejecting trust. Maybe try to work on separating the two?

I pushed away/left my Ts when I had thought, for a while, that they were no longer useful or there were more negative effects from therapy than positive repeatedly. I also refused "helping efforts" when I thought they were off the mark and not relevant to my situation.