Sudden errors with images and 404 on comments

I was working on my blog scheduling posts and literally ‘suddenly’ was no longer able to upload images. I click the upload button, but there’s and the bar runs, it shows 100% but nothing happens. Go to media and it’s not there.

I shut down and went to sleep. Next day had emails saying people were getting 404 page not found error when they tried to leave a comment.

I hadn’t installed anything new. I then updated commentluv, but that made no difference.

I have checked the permalinks, but can’t see any problem with them, although there seems to be some rogue # etc in the url (i.e. https://www.diaryofafirstchild.com/2011/12/23/friday-features-becoming-crunchy-and-liberated-family/comment-page-/#comment-)

I changed permalinks to default – made no difference.

Changed them back to Day and Name – made no difference.

I have deactivated all plugins – made no difference.

I then upgraded to WordPress 3.3 – made no difference.

Can anyone help me? It’s 1.29 on Christmas eve and this is driving me mental.

Thanks in advance!

Blog is https://www.diaryofafirstchild.com