I’m kind of in a similar situation. However, I’ve told my therapist that I have APD. He didn’t look into it at all until I brought it up a second time. He just couldn't see until I gave him examples real to me. Then he saw it, and he realized he has other patients that are APD as well (Guess its hard to see one when we APDs never show how we really feel

). But anyways, for an AP to share something like that it’s almost like it has to be forced out. Not by the therapist, but by themselves. Something has to happen to make that risk of rejection, embarrassment, and misinterpretation worth taking.
The big thing about APD is its going to take time to work at it. ( Lots of time…

) As much as we may want to share and disclose, what ends up happening is we have to wait till it’s forced out. Something has to happen that makes us feel like there is nothing else left to do. That something can be lots of things; maybe it’s just time; maybe its problems with work or relationships escalating to the point of hopelessness; maybe something completely different.
When something finally pushes us to share a part of us it feels great; especially when that break-through is shared with someone who can help. But not to long after the feeling is gone and it starts all over again. As far as I know this is what seems to be the pattern until trust is no longer an issue. Someone you’re able to have complete trust in seems to be what I’m looking for, and I assume others around here are too. A relationship like one has with a therapist probably isn’t ever going to be one of complete trust. But that doesn’t mean they are useless in the pursuit of someone to trust. During a “break-through” they can be most helpful as to what your feelings and thoughts mean and why you have them. And when you’re feeling hopeless at least you know they are there; an “Ear for rent”.
The breaking point that allowed me to say I have APD was, coincidently, when I found out about APD. Like many here, I read the definitions and descriptions and knew right away THIS IS ME! Similarly to you, in the past I feared I would be told nothing was wrong with me if I were to reach out. However when I found out about APD, I had proof something was wrong! I had a name and no matter how scared or reluctant I felt I had to share it in hope of help.
If you are afraid he won’t see the APD in you because he does not have a lot of information to work with, tell him things you have done that are examples of the APD descriptions.
I’ll give you one: “Is unwilling to get involved with people unless certain of being liked”.
About four months ago I quit my job at the local grocery store because of stress and depression. I had recently been coming in late a lot and calling in sick as well. So, when I quit it was very abrupt and sudden. Since then I have given myself a very hard time about not being dependable and for quitting without a two week notice. I really regretted quitting but I couldn’t even go back to shop I was so ashamed and fearful.
Just last week my brother applied for a job down at the same store. When he came back he said the store manager missed seeing me around and that he thought I was a great employee. So what do I do? First thing next morning I go down and apply to get my job back. I was still very worried, but I knew that I was welcome. My therapist and I had a good laugh at that because it really is so typical of and AP.
Hopefully your therapist is right for you, and he will understand where you’re coming from as you open up. I know what its like to have a therapist frustrated with you, and wondering if you should find someone else. It’s going to happen, but try not to get down on yourself for not sharing how you feel, the fact that it takes time cannot be stressed enough for AP’s. I really hope you find this helpful. Its all opinion, but I think a lot of us here feel the same and can relate.