I Am A Courier. I Have Pain In The Bottom

I am a courier. I have pain in the bottom of both feet that I feel at night. It's a dull pain and will go up my leg to my knees. I feel it when I am in bed at night and still have it in the morning, but don't feel it during the day. I often have leg cramps at night and have to get up to walk them off. The leg cramps will go away, but the foot pain doesn't.