There is a lot involved in your story and why you feel, think, and act the way you do. A lot of it sounds like it adds up, such as we know that things like long hospitializations and surgeries as an infant do interfere with attachment. And insecure attachment is related to having difficulty with relationships and boundaries and all of that stuff. It might help to read about these topics and see what you find that you can draw from in understanding yourself, and figuring out how you might like to change.

I also feel that it is important to discuss things that concern you with your therapist. It sounds like you have a good therapist, who tries hard to help you, and hopefully is someone you could trust. Maybe learning to trust is one of the issues you need help with. Your therapist will either help you feel better about the things you are concerned with, in the sense of answering your concerns so that you know which things might not be applicable, and also help you to work on the things that do need to be addressed.

That said, I agree with a lot of what Special K has told you about the purpose of diagnosis. It is only useful insofar as it helps somehow. It is easy to identify with personality disorders because lots of people have those traits. It becomes a disorder when a trait or combination if traits is excessive and causes problems for you. There are some parallels between Borderline Personality Disorder and Bipolar, so you might also relate to symptoms because of that. There are people who have both though, so the short answer is to go back to telling you to discuss it with your therapist. You could even print this thread or part of it if that makes it easier.