Chessteruk
"i noticed the 'Auto Forward All Email' box has an email address in it that is not mine."
That certainly sounds like very bad news. ☹
"Does this mean someone has hacked my email account" - if you did not set that auto forward then someone else did, so yes it looks as if your account has been hacked
" I have changed my password now. " - that's good but if the hacker still has the email account open on their device they can still access the account. To stop that you need to sign into the My Virgin Media account here
https://www.virginmedia.com/my-virgin-media
with the hacked email address and the new password. Then click on "Account settings", then "My Virgin Media account details. Then scroll down to the section "Sign out of all signed in devices". Once you click on "Sign out all devices" that will shut the hacker out.
" forwarded all my emails to themselves " The auto forward function in VM webmail only forwards new emails as they arrive so the fact the auto forward is on does not mean they have forwarded your emails that were already there. However..........
"deleted from my inbox,sent items etc" - if those folders are now empty then it does seem that the hacker has deleted them.
"What should I do" - the first thing I would do would be to check all my other online accounts such as eBay, Amazon, social media and any others that you have.. The reason I say that is because hackers often take over an email account to make it easier for them to hack the onlne accounts linked to it. They can easily reset the passwords for those other online accounts using each online site's "Forgotten password" process for example. They can also use your email account to set up new online accounts on other websites. I would say that's that's the biggest worry and potential threat that you have rather than the missing emails.
"can Virginmedia help reset my mailbox to an earlier time so I can retrieve my emails? " - assuming you are still a paying VM customer with a VM broadband account for example, you can certainly ask them but I think it's a long shot. VM do not seem to keep back up copies of emails. Sadly, if this VM email account is just a standalone account then there's nothing VM can do I'm afraid.
One of the forum team (VM staff who support this forum) will contact you via this thread but I am not sure if there are many on duty today as it's a Bank Holiday.
I certainly hope that you can get this resolved but it is a real worry for you.
Coenoby