Know at least in part what you're going through. Submitted by crap draft of my PhD thesis in 2003 and then spent 4 years in full time non-academic employment doing the huge list of revisions in my spare time and commuting on a train!
You're doing all the right things - getting help, seeking therapy (I wish I had done earlier), being fair to yourself.
It might be helpful to try the following:
Remind yourself why you started the PhD. Look back before you accepted. Might help to talk to friends about this. Why did you accept the challenge? What about yourself meant that you had to do it? Everyone's ignorant of what it entails until after completion and every PhD is different but why did you start at all? Reminding yourself of how brave you were to begin with is important.
Next thing is to divide and conquer. Find the smallest, easiest task of all. It might be insignificant to the final work but it's something. For me it was a paper I had been putting off reading. I decided to code one small piece of it. Not the whole thing, not a reproduction of the results, not beautiful code, just something. For me, that broke the spell.
Finally, accept that it's OK to walk away. Like everyone else here, I believe you can do it - I can feel it from your blog post. That said, it's OK if you don't complete it. Yes, there will be regret but you'll go on to other, brighter things, unshackled and free. That's OK too. You don't have to complete everything you start, that wouldn't be fair to you. I know a good few that didn't complete for a myriad of reasons and they're all doing great. I think you should give it a go but the world won't end if you don't.
You're doing all the right things - getting help, seeking therapy (I wish I had done earlier), being fair to yourself.
It might be helpful to try the following: Remind yourself why you started the PhD. Look back before you accepted. Might help to talk to friends about this. Why did you accept the challenge? What about yourself meant that you had to do it? Everyone's ignorant of what it entails until after completion and every PhD is different but why did you start at all? Reminding yourself of how brave you were to begin with is important.
Next thing is to divide and conquer. Find the smallest, easiest task of all. It might be insignificant to the final work but it's something. For me it was a paper I had been putting off reading. I decided to code one small piece of it. Not the whole thing, not a reproduction of the results, not beautiful code, just something. For me, that broke the spell.
Finally, accept that it's OK to walk away. Like everyone else here, I believe you can do it - I can feel it from your blog post. That said, it's OK if you don't complete it. Yes, there will be regret but you'll go on to other, brighter things, unshackled and free. That's OK too. You don't have to complete everything you start, that wouldn't be fair to you. I know a good few that didn't complete for a myriad of reasons and they're all doing great. I think you should give it a go but the world won't end if you don't.
Best of luck, will be thinking of you today.