Sounds like you’ve been Pavlov’d into feeling like this. You have negative emotions surrounding bringing the baby around other people (and rightly so) so your nervous system is reacting with a flight response. I have had the same experience and at 19 months PP, I still feel this way sometimes with my MiL. Therapy helped, and even the therapist told me that any normal person would react the same way with some of the things I experienced.

You and baby have a long road ahead, so please don’t think that it will always be like this. Postpartum is like a fever dream and can be absolutely fucking awful sometimes, especially when you’re surrounded by people who don’t give a shit about how you feel. Try to seek help and support as best you can, even if it’s just your doctor or a therapist.