Getting Virgin emails through Outlook

I know many people have this problem but I'm just going round in circles. I use Outlook for 3 different emails and it all worked fine until a couple of weeks ago, then the Virgin email just froze. I contacted Virgin & the first person I spoke to was fairly helpful & helped me generate a password so I could use my A/C. He then said I'd need to speak to his technical team for more help. I was passed onto them, but they said there was nothing they could do & I'd need to go to the "Gadget Rescue team" who have a No Fix, No Fee policy.
I do not want to pay for something that was fine before Virgin changed everything, so I fiddled around and managed to get my Virgin email onto the new Outlook. It worked fine for a couple of days & has now stopped receiving emails again. I am getting a box come up approximately every couple of minutes asking me to enter my username & password, but nothing I do is working. I can't get anything to work & every time I close or cancel the box, it returns soon afterwards.
Is there a way to sort this out, once & for all in a SIMPLE way. My brain is totally frazzled & i feel like throwing the computer out of the window!! I need an Idiots Guide, if such a thing exists!