That is absolutely true. It took several years for me to become securely attached but much of my trauma revolved around attachment so I needed to become securely attached in order to resolve it. But the process of becoming securely attached was so incredibly difficult that I almost left therapy many times along the way because it often felt so retraumatizing I didn't think there was any way I could ever get through it without going completely crazy. The insecurity and intense neediness and desperation for connection often led to an equally intense need to pull back in fear and anger when my T didn't meet my need for connection. Those opposing feelings would occur simultaneously, so I experienced a debilitating state of both reaching out and fighting the attachment. This happened repeatedly throughout the first several years of our relationship, and it was my T's ability to tolerate my distress without increasing my neediness by reinforcing my belief that I could not tolerate the feelings without his help, and without reacting angrily himself when I was raging about him ignoring and abandoning me, that eventually helped me move past it. Basically, he "sat with" my feelings until I could do it myself.
I think it's crucial for the T to balance responsiveness with non-responsiveness so that we have the opportunity to learn that nothing bad happens and the relationship still exists when he can't be available every time we ask for reassurance. Being "too available" and responding every time we ask for a response doesn't afford us that opportunity because we come to expect that reassurance, but that expectation isn't realistic. But I don't mean that a T should intentionally withhold contact after promising it at a certain time or on certain days because that would be unnecessarily cruel and manipulative. If you have an agreement that there will be between session contact to "check in" twice a week and the agreement includes a response from your T on those two days, then it's important for him to follow through with that unless something unusual and unexpected prevents him from doing so. But at some point we still have to learn to sit with the feelings we experienced as young children when our parents didn't meet our needs, because there will be times when we want responses from our T or from other people in our lives but we don't get those responses, and we need to learn to tolerate the feelings that get stirred up when people don't meet our needs. We need to be able to work through those feelings in therapy so that we don't resort to our default position of believing we are being abandoned or rejected when someone doesn't meet our need for connection.
My T provided some reassurance early in our relationship, but certainly not every time I called him or emailed him asking for reassurance that he was still there and not giving up on me. Naturally I was hurt and angry when he didn't respond, but that didn't lead him to respond more often because he didn't want to reinforce an unrealistic expectation that he "should" respond more often in order to prove that he was not like my parents. And gradually he began responding even less frequently, making me wait while he monitored my reactions from a distance. Of course I didn't realize he was still there in the background, riding out the storm with me and keeping an eye on my level of distress, because while I was riding it out I thought he had completely abandoned me. But those were old feelings that I had to work through in this relationship, and one day, after I finally calmed down, it occurred to me that maybe he hadn't really abandoned me after all. Maybe he had been riding it out with me, but in the background, waiting for me to come back out of the intense desperation and craziness again, and he would still be there. I remember emailing him with this new revelation, asking him if that's what was happening when I thought he had abandoned me. He replied saying yes, that was exactly what was happening, but it was important for me to reach that realization myself because it meant that I was beginning to see the bigger picture. It meant that I was beginning to understand that our relationship still existed and he still cared deeply about me even when he didn't meet my need for connection and reassurance. That was an important insight because it meant that I could hold onto our relationship in the abstract, without something concrete and tangible reminding me that it existed even when I felt detached and disconnected from him.
So there were many steps and milestones along the way, and it wasn't a linear process at all. External stresses and problems sometimes undermined progress temporarily, and trauma related triggers often sent me into the approach/withdraw tailspin, but those meltdowns became much less numerous and less intense over time, and now I think it's pretty safe to say they're extinct.
And now I can look back and see how the process unfolded with much more clarity. Now I can understand why my T never told me to stop calling or emailing him if it was causing me so much distress. I wanted him to tell me to stop because I couldn't get myself to stop, which makes sense now because the unresolved attachment issues led to the simultaneous approach/withdraw conflict that characterized our relationship for the first several years. One part of me desperately wanted to pull back in fear and anger, and another part of me wanted nothing more than to hold onto his leg and never let go, so I would often find myself calling or emailing him in a state of bewilderment because I did not want to call or email him but I could not stop myself. The part of me that wanted connection and attachment was very strong, which makes sense because we are hard-wired for attachment and connection, so reaching out was normal and healthy even if I couldn't get the response I wanted at the time. If he had told me to stop calling and emailing him in order to minimize my distress, I wouldn't have been able to work it through. It would have suppressed the entire process, which would have provided an illusion of having resolved it, but it would have reemerged in another relationship eventually when those same attachment needs were triggered. I had to go through the whole process in order to resolve it. I had to experience the fear, anger, and desperation of unresolved and insecure attachment in a relationship with someone who understood what was happening and could tolerate my distress, and then I had to emerge on the other side with a secure, serene kind of attachment that encourages closeness without helplessness or enmeshment.