Don't you be ashamed. You remember that he made you feel more loved than anyone else in your life ever had before, and so the withdrawal is the WORST. Remember, the loving part IS the mask - not the cruel part. The cruelty is who he REALLY is.
Let's think about this. You don't know at this juncture whether he will or won't try to contact you as a result of your 'revenge'. What would you feel if he does respond? Elation? Joy? Happiness? What if he gives to a malignant response where he's cruel or dismissive - or - a classic narc play - no response at all??
How long will it be before you feel that ebbing and think to yourself 'oh God... now he knows he has me again'. And what happens then? Fear? Crippling anxiety? Dread? Do you want to put yourself through that again? Think of the end result, not the one where you hope for his hoover, because that is about YOU needing HIS validation, and that requires introspection as to why you need that. I know, I went through this myself.
I have done 'revenge' on my ex narc in spectacular style when I've been in agony, and I've felt the same as you - genuinely suicidal and in pain. I've taken a month off on the sick in the past, at that sort of thing. I had countless counselling and meds. It really is keep trying to quit, just like it is for any addiction. It is agony I agree, but it is withdrawal and you have to keep in mind that there is something in YOU that wants and craves what you are missing from HIM. Not the memories, not the approval, not the (albeit you didn't know) 'conditional love'.
On a few occasions I took 'revenge' on the ex now I think about it! Some of them have been amusing and some have been a mic drop moment. But the OW stuck by him. Why? Cos he'd fed her all the BS he'd been feeding me. What do you think he's doing atm? Feeding her BS. She's getting exactly the same treatment you first got and eventually, she'll get the shitty treatment too. I'm not ashamed to say that I took a lot of satisfaction in that knowledge, and of course, he did the same to her eventually because that's what narcs do. Hopefully by the time he drops her and returns for a hoover, you will have moved on enough to be tempted, but not return.
As I say, we all have bad days. Bad weeks, bad months. I caused a situation deliberately for mine to end in November 24, and here I am in Feb 25 and I'm still grieving and I will be for some time - but then comes recovering. Just like being an addict, you have to reflect upon your own reasons for wanting something you know is bad for you and where does it stem from? Reflecting on this helps distract from the focus on him, and the 'good times'.
I loved my ex. Thought he was sexy, handsome, good in bed, creative, had 'loads' in common (but I can expand on that BS with a simple example of how that wasn't true and likely isn't for you either, if you wish). But he was a lying, cheating, gaslighting, abusive, twat. So why did I want his 'approval' so badly? Why was his 'love' more important to me than anything else? I know the answer for me. Have you thought of yours?
You're strong, lass. You've got this far. <3