Month old has reflex grunts and spits up all night can't sleep on back

So my one month old daughter has reflux. Its seems to be the worst at night. She is breastfed. After feeding her I keep her up right for 30 minutes sometimes longer.. before putting her down. But not even a minute later she grunts and makes noices like she's clearing her throat. She spits up a lot and then starts fussing. If she is laying on my chest or in my arms she's fine. All night we have this issue, some nights are worse then others, I've gotten up and just walked around the house with her, cleaned her up because she usally has spit up all over her face and bed and she'll go back to sleep but when I put her down she spits up and just seems uncomfortable. I've elevated the mattress but that seems to have done nothing. I don't know what else to do? I'm losing sleep but at this point I just want her to feel comfortable in bed.