Choking during feedings

So I'm a FTM and I get terrified every time my LO chokes while drinking her bottle. I tried propping her up when feeding so she basically sitting down kind of straight. I tried different positions but nothing seems to be working. She sometimes pauses while eating which I think then milk pools in her mouth and she goes to suck again but ends up choking. My mom tells me to calm down all the time but she's 10hrs away from me. It's just me and baby home all day until my SO gets home from work. So each time she chokes, I help her but can't help but panic. Suggestions? ?