Hugs to, you. I have bipolar 1 and several anxiety disorders. Not BPD, but I am familiar with it .... having both conditions and motherhood....well, I understand a lot of where you’re coming from and no judgment from me, at all. I’m a mom, too. It’s TOUGH when they are so young and totally dependent.
On another note, please talk to your therapist about how you feel. I can’t give official legal advice, it I’m familiar with that area of the law from my profession....and social services will not be “in touch,” in my opinion. There is no imminent danger of harm or neglect happening. You’re ok there and You have my support. Talk to your therapist, it’s fine.
PS: Two things....I think you need your own time and also time with just you and your H. Express those needs. I wish I’d have been more assertive about that....life is the family, not revolving around the child, IMO. OH...another thing. It gets MUCH easier .... mine is a healthy, happy teen (she doesn’t like children!

).
xo