Media upload trouble

Hi there,
it seems impossible for me today to upload images on my website. I’m using Woocommerce and I was trying to upload an image to a product when everything broke down without finishing to upload it. If I look at the media library I can see a lot of broken icons (so much that if I scroll down they don’t stop to appear) of the image that I’ve tried to upload and nothing else! All of the other images already uploaded are disappeared. I tried to upload the image directly on the server but nothing changed! Can anybody tell me what happened and how to solve it? PS I uploaded some image the last week and everything was working well.
Thank you in advance