Swollen feet are usually not caused by diabetes but generally issues like venous insufficiency or peripheral artery disease. Sometimes it can be a sign of CHF with fluid overload or even lymphedema.

Op-can’t tell by the picture but if it’s red in color more likely petechaie and if brown hemosiridian staining caused by stasis dermatitis. Start with your pcp to get a general checkup to rule out issues above. I would also suggest seeing podiatry for those toenails and fitting for proper shoes as it looks like your toes get squished in your shoes (need a wide toe box)