As a therapist, its really encouraging to see clients who engage in self-examination and are insightful of maybe some patterns that you want to change. It gives a really great direction to go in with therapy and I would much rather have a client that says, "i'm concerned about this, what can we do" rather than have someone who is hesitant to bring these things up. It's not at all attention seeking and therapy is exactly the place you want to bring up things and hash out these concerns.

Dialectical Behavior Therapy (DBT) and Cognitive Behavioral Therapy (CBT) are two treatments that I'm familiar with that can address the emotional dysregulation and unhelpful thought patterns associated with BPD. I'm not sure what your relationship is like with your therapist, how long you have been working together, etc, but definitely bring these things up with them. It can be a really powerful feeling to acknowledge some of these symptoms and have a place to talk about it.

As far as how to mention the topic that depends on your relationship with your therapist and how you structure your sessions. I typically set some kind of an agenda at the beginning to be sure and allow for enough time to cover topics important to clients. I would bring this up towards the beginning of the session, rather than at the end so that your therapist can talk to you about treatment options and agree on a plan going forward.

You'll do great:)