I’d say that if you are able to maintain friendship is a positive sign that you could maintain connections with people. But I’d say that continue pursuing this man romantically isn’t a good idea and it’s not his or his children responsibility to make sure you experience motherhood. Even if there is no mother at all as she passed away, it still doesn’t mean other people’s kids need to be adopted by anyone else. That’s just not how it works. Perhaps you need to stop seeing this man all together as it is just causing you pain. He’s not available for you and neither are his kids.

Are you seeing a therapist? If not, as previous poster suggested, you would greatly benefit from seeing one. Therapist specializing in BPD would be probably the best bet