Hi Paper Heart and welcome to PC!
I’m sorry for your ailments and condition...it’s a crappy way to live, but it is the life we are to live. Anyhow....
What works for me is sometimes a good hard focus, looking at and noting my surroundings....giving a hard look at to stay focused. Sensory overload, multiple alters yammering at the same time, anxiety or stress, flashbacks, switches, surprises, conflicts, boring moments, all can trigger all the time every day.
I don’t rely on tactile sensory input because that’s hard to do while driving and I don’t carry ice cubes with me every where I go.
For me...good ol mental work is what it takes. In super markets (loud, noisy, colorful, smelly, bright lights....) I usually grab a product and start reading the labels noting color, size, content.....move then check out another...till I calm down and collect myself. Even when driving I start reading signs, license plates, looking at sign colors noting the reflection, shape, material....looking at the bugs stuck on the windshield....anything to get the juices flowing again. It isn’t immediate, but after awhile I do come around.
All methods of focus and distraction. Sure it feels like pulling out of molasses’s, but eventually one can escape molasses.