Zooropa, I don't call my T but we do use email between sessions. I always used to be worried that I was bothering her by emailing, and there got to be a point where I really wanted to set boundaries around it -- I made her promise to tell me if the emailing got to be too much. Are you concerned about what your T's policy is on calls? Is she open to them, or are they only for emergencies? (I feel lucky that I can email for between session connection -- I think it would be hard to feel like I was only allowed to contact her during an emergency, but I think some T's do have this policy.) Maybe you could talk about how she feels about calls during your next session?
The other thought I had refers to you saying you often feel worse after calling her. I think you're on the right track in trying to analyze what it is you want from her during the call. Maybe once you're clear about that, there will be less chance of disappointment leaving you feeling worse? Maybe during session you can talk to her about what it is you want from her during these moments -- it might help you understand yourself better as well as give you the chance to discuss what she can and can't do during a call.
If you feel like you need to connect with her or at least tell her how you're doing, and she has been OK with this type of call in the past, I would think, go ahead and call her this time, and then maybe during session you can clarify a little more about future phone contact?