EBF and bottle

Hi ladies, I have been giving my one month old a bottle here and there when I pump on the go and she takes it great, never any problems. However, when I breastfeed her she is very gassy and today for the first time she projectile spit up all over me. I do think I have a fast let down and maybe she’s eating too fast or taking too much in. I love breastfeeding her but I don’t want her in pain. Any tips on what I can do to help this?