Thank you for contacting Extension and sending informative pictures. Have you noticed any insects on your potatoes? If not, you are dealing with a blight. There are two types of potato blight, early and late blight. From your pictures, it looks like late blight because of the curling of the leaves and other damage. We have had challenging moisture conditions with heavy rain and cool conditions which contribute to blight. Here is an Extension article about late blight:

Late blight of tomato and potato | UMN Extension

Here is an article about growing potatoes, with a section about growing in a home garden. Early blight is covered in the article. Be sure to read the section about potato tubers, under selecting plants. We recommend you not use previous tubers from years past, especially if you have a blight problem:

Growing potatoes in home gardens | UMN Extension

Good luck with your potato growing and hope you can resolve your problem.