i disagree w Scarlet in that if you are not secure with yourself, you still can be secure with others. I feel like that is a basic premise in attachment. My relationship with my best friend is about as secure as I can imagine it being. I pretty much know that she won’t ever stop being my friend, but even after 18 years (OMG), 7 of which we lived together, I still can jump to the place where I have finally pushed her over the edge and she will be done with me. That is my insecurity talking. Mine is fearful-avoidant, so i default to that when I am worried about our relationship. I know there are many different types of relationships one has, and differing levels of attachment security depending on that relationship, but i think the more vulnerable you are in a relationship, the easier and quicker you can devolve into your insecure attachment patterns.
Rainbow-i agree that you aren’t secure in your attachment with your T. If you were, you wouldn’t always be so preoccupied (used this term specifically

) with all the minutia of the relationship with your T. You wouldn’t spiral down just bc she said she has a family thing and won’t tell you what it is, or feel left out bc you didn’t know her boyfriend’s name. You wouldn’t constantly agonize over the feeling like you pay too much, or any of the other things that makes you think the relationship you have with your T is anything “less than.”
If you were secure, you wouldn’t be so triggered and looking for reasons to make sure your relationship is “real.” If she said “I need to cancel next week, I have something to deal with my family,” you may be a little disappointed or worried that something might be wrong, but you also would understand, and deep down you know that when you see her next, she will still be the same T for you.
ETA: Someone should count how many times I used the word relationship!