Anyway she's in her late 30s and she's never really been into having kids, but it's never been off the table completely and for a couple reasons the possibility of this might be getting slightly more 'real'. And so this has been bothering me and dysregulating me very recently. I think these fears are mostly irrational for now but maybe not irrational enough for me to convince myself of that

I'm a lot younger than she is, and I'm still figuring out finding a family of my own. At this point in my life the dynamic just causes me anxiety. I wish that my FP could be someone closer to my own age and in the same place that I am, because well, a 'safe' person to attach to is someone who isn't going to have a child to think about.
Every time I think about this I feel the 'sick' feeling of abandonment fear. Tight throat, unbelievable tension, tears, rage.
I'm so exhausted of feeling so emotionally dependent on this person and so drained. But the thought of not having anyone who understands me so well, someone I know and trust so well, is horrifying. I feel like this friendship that found me is a once in a lifetime thing. But I think this situation would be my breaking point, or I just wouldn't be a strong enough person to try and put myself through all that hell just to be a good friend.
I'm not sure what I'm asking the forum. I think just writing it all out maybe gives me some distance. Or any tips to get through the emotional distress response. Or just remind me that this worry will die down with time.
My life and relationships are going so well otherwise that I think I just need something to latch onto to freak out about.