As an essential worker, wearing a mask for hours can be uncomfortable, but they are necessary to slow down the pandemic. However, there are a few things that can make wearing a mask a little easier.
My first suggestion would be to bring multiple masks with you to work so you can change them out every hour or so. This may already be mandatory where you work, but if not, it may help with feeling icky or cramped in one. Also, make sure to store them properly when switching from a dirty mask to a clean one.
Another thing to remember is to wash your face as soon as you can after coming back from working. A lot of people have been talking about how they are getting acne from their masks, so this can prevent it from worsening. In fact, if you can somehow wash your face during a break, that could help too—just remember to wash your hands thoroughly before touching your face.
If you ever get an itch under your mask, never touch the outside of the mask to try to scratch it. If you really need to, put on a glove and do so, then throw the glove away. Or, if you have a second, find a space to take off your mask, wash your hands, and do something about that itch.
Lastly, always wash your masks before wearing them again, especially after a long day of work. Washing and drying on the hottest settings is also the safest bet to kill any bacteria or viruses.