Something that I think is helpful to do as early as possible in an estate is to go to the office supply store. In an estate, the paperwork quickly starts to pile up. If there is real estate, all of the utility, tax, mortgage, insurance and other bills are coming in regularly. Notices about pensions, social security are coming. Medical bills and EOB's, bank and brokerage statements, the list goes on and on. Your estate attorney can help sort through those items, but if you can start to organize and prioritize all of the paperwork that process can go more quickly.
So, I would suggest getting a box of maybe 50 file folders, some labels, a marker and a couple of bankers boxes. As you open mail, start a folder for each separate item- bill, statement, letter, whatever. As time goes by and you get a sense of what is what, you can consolidate and even eliminate some files. Use the boxes as your portable file drawer. If you have to go by the decedent's house to pick up mail, you can use a box to take files and mail home where you can work on them in a more familiar and comfortable setting.
Just the feeling of having paperwork in files and boxes can help the stress and sense of being overwhelmed diminish. And that is an important step forward.