I have to face it that it's time for me to begin IC for myself so that I take control over moving forward (in whatever direction). And no, I still have not told anyone (other than here) what has happened. I am ashamed for him
I don't know you well enough to know if you really need IC or not, but I can tell you that if you don't start putting you and your needs first then you will never properly heal from this. His healing is up to him, and yours is on you. Yes he did this and broke the M, and broke you, but he can't put you back together, that has to happen from within. He can support, and hold the pieces while you glue, but he can't do the work for you.
In addition it sounds like you are waiting on therapy to be the magic bullet to cure/heal/help him. There is a ton of stuff he can and should be doing on his own.
He should be reading books on how to help your spouse heal, he should be giving you all the support and reassurance that you need. He also should be as transparent as a window, and as kind as the pope.
Lastly it is not your job or responsibility to carry the shame of his choices. Find one person to share with. A sibling that won't judge no matter your decision, a pastor, a coworker that has BTDT, but someone. YOU will find that getting it out, sharing with someone helps to lift the burden. Don't get me wrong SI helped me through all this, and probably kept me mostly sane, but nothing takes the real life support that you can get.