I submitted my thesis a few weeks ago and have totally taken the past few weeks off from anything PhD related, I have just received my viva date and it has brought it all crashing back lol.

Anybody got any tips on how to prepare for the viva and not get so nervous I forget my own name.

I can tell you how I prepared for my own viva.
First, I knew my thesis inside out. I had it full with post-it notes, where I had everything written and different colour post-its marking the beginning of each chapter. Also, on the laft blank pages, I summarised the main points of each page.
Then I prepared answers to the most "important" viva questions I found online (why I did this research?, What is my methodology and why?, How I chose my participants?, What are my main findings?, What other research have I used a lot and why?, What is my contribution to knowledge?, How will I disseminate my research?, What are my future plans? etc). I wrote down the answers, and I learnt them almost by heart.
A few hours before my viva, I had a mock viva with my supervisor and a colleague of hers. This really helped me a lot.
When I went into my viva I was really nervous. I remember that one of the examiners wanted to talk about an ethical issue that came up during the research, and he insisted on asking me "what if....". I was asked about two paper that I referenced a lot (and I was really lucky, because that morning I had read them again, so they were fresh in my memory). I was asked about my methodology, the reason for doing this research and the dissemination of my results.
The whole thing must have lasted about an hour, but it felt less. When me and my supervisor got out of the room I remember asking her if I could breathe now!
I was called back 10 minutes later and I got really minor amendments (10 minutes work).

If I could do it, then you can too!
Just be as calm as you can. Know your thesis well and be confident about your work!

Well done on passing and getting minor corrections, I practically wrote my entire thesis in 6 weeks so the best I can hope for is major corrections I reckon. I just want it over with now.

I'd echo most of the advice above. The one thing I'd add, based on my own experience is kind of obvious, but perhaps easily misunderstood: be prepared to defend your thesis and don't panic when you have to.

Despite knowing more than most about the PhD process (it goes with the FindAPhD Content Ed' role) I still slipped into the trap of thinking I had to carry my thesis through the viva unscathed and that a successful examination was about confirming the perfection of my research and ideas. It isn't. It's about making sure you can explain and justify the decisions you made and the approaches you took, even if the external disagrees.

I faced a pretty tough question early on: 'your thesis is about x, yet I'm surprised not to see y anywhere in your bibliography'. For a few seconds that felt as if I'd started a driving test by pulling out of the car-park, speeding and failing to indicate. In fact all I needed to do was say 'yes, but my objective with this project was to move away from y and examine x in the context of z'. Which was exactly what the examiners wanted to hear. I don't think they actually agreed with me that x can be discussed without y, but they recognised that I'd made a plausible decision and was able to justify and explain it to them.

Basically, don't panic when you get the tough questions. Dig in and defend your thesis. You'll probably do a lot better than you think you are. I got minor grammatical corrections in the end (ironic, given my day-job).

Good luck!

That's really helpful, thank you. My fear is not being able to answer those tough questions and the whole thing unravelling from there lol.