I had the hardest time with this (and sometimes still do). In my regular life I am pretty responsible and together and worry a lot about how I am making other people feel, so the idea that I could just contact my therapist for help whenever I wanted to without knowing if she was busy or wanted to hear from me or whatever was terrifying. Often it helped to talk to my T at the next session about how she felt when I called, why she wants to be there for me, etc. We also talked about what would happen if it became too frequent, which was that we would work more on my self-soothing strategies or talk about ways for me to try to delay calling to see if it would pass (we haven't needed to talk about any of this yet; she has mentioned before that she knows I try other strategies before calling, which is true). Early on my T said point-blank, "I would never just tell you to stop calling me."

I have actually been surprised by how well the outside contact works for us. I can usually sense specific circumstances when I'm going to want her help and other times when I feel bad but don't really need her. I have also explained to her some things that do or don't work for me, like I would rather wait and be able to talk to her for a few minutes longer when she is free and more relaxed than have her try to call me back immediately between clients. I think it has been super meaningful to be able to rely on her and to feel her caring and maybe get myself back on track before I completely descend into the pit of despair. Sometimes things just can't wait until the next session. I also agree with Satsuma that part of the value is working through things and seeing the relationship become more sturdy. That has obvious outside-therapy relationship parallels.

To answer your specific questions, I am seeing my T twice a week during this phase of my therapy. Currently I call her maybe once a month or so, just based on whether something big or stressful is going on in my life. The most I have ever talked to her was the time around the U.S. election when my life was (coincidentally) also a complete mess. I think I talked to her every day that week, between phone calls and in-person sessions. That was a rare circumstance, but I think part of the point is having the experience of somebody being able to respond flexibly and consistently to my needs.