OMG it is so nice to read this as I'm going through the exact same thing. My expected completion date is Sept 1. But I'm terrified! I still feel like I have so much work to do and not nearly enough time... and to boot my sup is out of the country until then... email conversations are VERY tough right now.

Good luck... and it's nice to know someone else is handing in the same time!

All I can say is "I hear ya"
I am in my 6th year of a supposed 3yr PhD program and I am struggling. There have been many many many times when I have wanted to walk away.
I guess it all comes to down to why you're doing a PhD and what else you want to do. I want to teach/lecture at uni... and to me a phd is a necessary evil. I don't enjoy the research I'm doing but am sure I could enjoy research in another area (who isn't sick of their own work after 6 yrs?).

There were many nights I cried my eyes out terrified of how much I hated it. And to be totally honest the only thing that kept me going what the feeling of shame I was convinced I would have if I quit. Which is such a cop-out! I think it would have way more brave of me to quit when I was so desperately unhappy. I am weeks away from submitting my thesis.... and I'm terrified. How good a job can you do when you hate what you're doing? I am freaking out that it's not going to be good enough, freaking out that i'll fail the defense and get offered a masters (I would lose my head if that happened). It is extremely difficult to get through the final few weeks of writing when you are in a state of terror... and to be honest I do have some regret that I didn't step away when I seriously started to think about it.

Now, all that being said... I am kind of glad I didn't drop it when the thought first came into my mind. Obviously in a few weeks I will be happy (and drunk).... and hopefully some time away on a beach will refresh my outlook on the whole thing. But I also think if you are feeling this bad about the work you should have a serious sit down with your supervisor.... tell them how you're feeling and hopefully they can shed some light on things and help you out. Who can expect to work on one project for years and not have moments they want to quit and throw the computer out the window?

Good luck... and just make sure you do what's right for you. Realizing a phd and the work that goes with it isn't for you... not a failure. all it means is just that.... the phd route isn't for you.