1) Edit your product and check if Product Image is enabled in screen options http://prntscr.com/enghz2
2) Disable all the third-party plugin and check if it fixes your issue.
3) If you don’t have Product Image in Screen Options go to Appearance > Themes > Install and activate Storefront theme – official WooCommerce theme. Check the product again. If you still don’t have the Product Image you should contact WC support.
In case you don’t have Product Image option only when our theme is enabled then provide me admin panel and FTP access to your site.