screamed at my toddler

today I lost it, my son is 3 and doesn't know how to listen in public and what really set me off is when he hollered at me loud at Wal-Mart causing people to stare.. He wouldn't stop going on and crying when we got to the car, and I snapped and screamed as loud as I could "HUSH YOUR MOUTHHHHH" I instantly feel like a shitty mom. this pregnancy has seriously made my nerves so short, I hate that I am this way. I have 20 days left to go and I hope I get my patience back. i feel so bad. 🙁🙁