I had a bout of plantar fasciitis a few years back, and while mine wasn't a severe case - I certainly agree that the pain can be pretty bad.

I rolled a frozen water bottle back and forth under my feet to relieve things when they got bad. Then I got into the habit of taking a bath vs showering, and massaging that painful area on a daily basis.

Fortunately for me, the problem went away and never came back (knock on wood.........) I still do the daily foot massage "just in case".