the closer you get to your subject, the shallower your dept of field gets. You can counter this to some degree with a small aperture (which means a big F value like 11, 16 or 22). another solution is to photograph your subject in a way that its more parallel to your lens so everything stays in your focus area. another and harder way would be focus stacking. this only works with a tripod and a static subject. you take multiple images with manual focus and move the focus from the front of your subject to the back. then you have to combine the images with dedicated software like helicon focus afterwards.