First, welcome to the community and thank you for sharing your experience. It’s not always easy to be honest with situations, but you are not alone. I have a 17 month old and when my husband hears me upset (like growling in frustration), he will come and take the baby from me.
For you, that sounds like an overwhelming, frightening moment, and I’m sorry you’re carrying so much guilt afterward. One impulsive scream does not define you as a mother. You noticed yourself reaching your limit, called for help, let your boyfriend take over, and returned to caring for your baby. Those actions matter, too.
Your baby was startled, and that understandably hurt to see. But “I frightened her in a difficult moment” is not the same as “I’m a bad mother.” You can take what happened seriously without turning it into a judgment about who you are.
You need support, not just more self-control. Your boyfriend may have been frightened and unsure what to do, rather than deciding you were incapable. You don’t have to guess what he thinks—you can talk about it when you’re both calm. You might say: “I was scared by what happened, too. I called you because I needed help before I became more overwhelmed. I know she’s just a baby, and I’m not blaming her. What I need is for us to make a plan so I can hand her over and recover before I reach that point again.”
Make support concrete: agree on a phrase such as “I need you to take over now,” arrange regular breaks rather than waiting for a crisis, and share the settling, changing, and household work around feeds. Asking someone else to take over when crying becomes overwhelming is a recommended safety step—not a parenting failure.
Have a plan for the next overwhelming moment. If you feel panic or frustration rising, hand your baby to a calm caregiver. If you’re alone, put her safely in her crib or bassinet and step away briefly to settle yourself, then return and check on her. It is okay for her to cry briefly while you take time for yourself.
Please also tell your doctor, OB, or another postpartum healthcare professional about the anxiety attack and how overwhelmed you felt. You do not need to wait for another incident or prove that things are “bad enough” to ask for help. If you ever feel you might hurt yourself or your baby, put her somewhere safe, get another adult involved immediately, and seek urgent help.
Get feeding support, too. Frequent feeding can be normal cluster feeding, including during growth spurts, but it can be exhausting. Frequent feeding alone does not mean your milk supply is inadequate. If nipple pulling is painful or feeds remain constantly unsettled, contact a lactation consultant rather than assuming it is only a growth spurt.
Wanting to give your baby the best version of you does not mean becoming a mother who never feels overwhelmed. It means making room for your needs, accepting help, and having a safe plan for hard moments. You deserve care in this family, too.
This community is here to support you so I hope my reply can help you find some comfort. You’re awesome momma. Sending you love and hugs 
