I don't think the lifting would be the issue, especially since you wear oly shoes. Sometimes it can be something weird with how you rest your feet, and sometimes your feet just hurt. If it is the lifting, your feet will adapt; mine did. Get some sleep, and if you like a nice placebo, do some kind of massage on your arch. I enjoy using plier handles and golf balls.
Random thought: Potentially could be due to how you squat; if you are leaning way to far forward or if you're letting your feet be unbalanced laterally, that could be part of it.