Use a frozen bottle of water to roll the bottom of the foot and stretch the calf muscles while keeping the toes in neutral position. You can progress to a tennis ball once the pain lessens then even something harder. If it hurts too bad SMR won’t work properly so use the correct tool for the job. Dig up some information on the arches of the foot..yes there is more than one. Its best to know what you are rolling out and how the foot functions in order to treat it.
once you progress off of the frozen bottle to the tennis ball you can start to strengthen the muscles in the feet by placing a towel on the floor and setting a weight on one end then use a crunching motion of the toes to pull the weight on the towel closer to you.