My son has been spitting up over the past couple of days, very small amounts, but he was sleeping on…

My son has been spitting up over the past couple of days, very small amounts, but he was sleeping on his back just now and he spit up in his sleep and choked a little bit and then stopped breathing. I was able to clear his airway and he's fine now, he immediately fell back asleep, but I have never been more terrified in my life. I'm probably not going to sleep tonight. 🙃