NImali: you could also try packing a warm woolen wrap that has the scents of home or something you find calming (if that requires pet hair-so be it :P) something you can fit in a pack to take with you. Taking a paperback helps, as long as you can read, but the wrap you can pull out and put across your lap or over your shoulders and unless it's july noone will look twice. (I suggest a hat or shawl, depending on gender, in the summer)
A thermos filled with something warm and calming, like a home made broth or favorite tea, can help, depending on the person. Taking the time to close your eyes and inhale and you sip can be very calming.
If you're really desperate that noone should know, and you're in specific situations where a wrap or thermos wouldn't do it, you can go for a scented handkerchief, again with soothing scents.
While humans have an awful sense of smell compared to other animals, scent is one of our main components for memory. Simply smelling something that reminds you of safe can make a big difference.
If you're big on textures, I may suggest a change in wardrobe slowly for warmer, fuzzier things. Soft sweaters and fleecey or short pile faux fur, or maybe silk or satin, or something with a specific feel to it. I found out not too long ago that feathers can calm me down as a texture experience, but they're not happening because I have cats, and I'd rather not have hacked up feather bits in the house, but I do have some lovely velvetloft sheets that are amazing for sleeping on (they're soft and well..velvety and thick, you'd have to look them up, it's a bit later and my words are failing me).
Maybe a small stuffed animal you can fit in a pack for reminder of better days? Edge of an old baby blanket?
Not many people are going to be going through what you're carrying, and the folks whose job it is to do that won't judge. They've seen much worse. A scrap of soft dirty wool or an old stuffed toy won't even make them blink :P
If those don't work let me know I'm sure I can come up with more :)
