Kimberly, those open offices OMG. I've been there and I feel you! Can you wear headphones while you work? Even if you just get the noise cancelling ones and don't actually play anything through them, it can really help drown out the background noise.
Take quick breaks to walk outside if you can, do some breathing exercises or a quick guided meditation (I love Tara Brach- she's on Spotify and YouTube.), don't feel bad about eating lunch alone if you need to.
Does your office have any little side rooms that aren't always in use? In my last open office, sometimes people would duck into one of those for an hour or two just to work alone. I recommend it!