The situation you described reminded me of 'intermittent reinforcement':
http://wik.ed.uiuc.edu/index.php/Intermittent_reinforcement

Strangely, when our behaviour only sometimes elicits the response we want from T, and when we can't predict when it will elicit T's response, the behaviour is even harder to stop than when the behaviour always elicits the response. So if T replied to your emails every time, it would actually be easier for you to stop emailing.

I'm sorry you feel ashamed of your needs and wants- I know how horrible that feels It sounds like you need to clear this up with T- is she saying that it's ok for you to send emails? I mean, is sending an email separate from the issue of replying?

Earlier this week, and very unusually, I texted T on the final day of her holiday and asked her to reply. But I also said 'I know you might not reply'. I knew that it was ok for me to text- no judgements, no shame. But I also knew that it was ok for her to choose not to reply (as she did). The next day she texted me as normal and neither of us mentioned the text from the day before- she didn't feel the need to apologise for not replying, or to tell me off for sending it, and I didn't feel the need to take her to task for not replying or to apologise for texting. This is actually very unlike my normal reactions, but because it has come about as an 'agreement' and mutual 'permission' between us, I'm somehow ok with it. I'm wondering if you and your T could come to a similar agreement- and whether this would reduce your pain?