Gently, it's also 6 days from a D-Day. You have to give yourself time.
Keep thinking: 2-5 years, assuming no new hurts - and each TT adds a 'hurt'. You might consider giving him one more chance to come clean, with the consequence that you throw him out for good if he holds anything back - but then you have to follow through if he covers anything up. Also, don't guarantee to stay, even if he comes clean. If he reveals something you won't accept, you can kick him out.
Also, I read you want your H to heal, but he has to do that for himself. Spend your energy on your healing. Yeah, it's exhausting - but it's especially tough on you, because of the TT. The hits just keep on coming....
Your grief, anger, and fear may seem overwhelming, but you have your feelings - they don't have you. It only seems like you're out of control. You can feel the lousy feelings and let them go, no matter how overwhelming they seem, though it's more difficult to do than to say. And it'll take a lot more time and energy than you think it will or should.
More IC? IDK - why not discuss and work this out with your IC?
Mean to him? Not as nice as you used to be? Well, yeah.... (IMO, you're still being too nice to him, but that's JMO.) Why aren't you trying to punish him? Besides, he knows he deserves mega-punishment, and he's just blame-shifting (though not in the usual way that term is used here). The guy keeps TTing you - that's a good way to end R, and it certainly increases your grief, fear, and anger.
Sh***ing on him? Boy, I wish I had thought of that - it could be a real punishment that hurts the WS without doing much damage to the BS. Every other punishment I've thought of hurts me as much as it hurts my W.... You may have done BSes all over a good turn... except most BSes probably don't want to add more mess to their lives....
I very rarely called my W names in the aftermath of her A, but I pretty much demanded she talk on my schedule and about the subjects I wanted to talk about. We talked for hours every day for weeks after D-Day and we stopped only because she got exhausted. I also made damn sure she was stepping up to the work of R - and that was from the beginning, long before I committed myself to R.
And every day I made a go-or-stay decision, sometimes several times a day.
I think you may be selling yourself short - feeling the feelings is only part of healing. Preventing new occasions for grief, anger, or fear is also essential - and that means calling your H to account and not letting him continue to hurt you more than you're willing to be hurt.
You can't make him a better human being, but calling him on his sh*t might guide him to figure out what changes he needs to make.
Sorry to ramble....