What's your hurry? If you take your time, and make a thoughtful decision based on facts, and not just feelings, you give yourself the chance to make a good decision.Ever notice when things happen fast, you get caught up in them, and have no time to think? I hear all your emotional arguments, and they sound great on paper at least.
I highly hope you give him time to see is is words, and willing attitude, translates into positive actions, that match those words. Let him go into therapy for himself, and by himself, if he is so willing to help himself. He has been lying, and cheating, using, and abusing, so long, it would be unwise for you to give him any crutch to do what he has to do for himself, to make him better.
While he has finally gotten the right idea, its him that must take the right steps at this time, and make his own decision without your influence.
That helps him be responsible for his own actions, and lets him put more than words on the table. There is absolutely no hurry, or reason for you to jump back into anything with him at this time, because he needs space to work on himself.
It does neither of you any good to ignore what has happened, and not recognize what is right for you both, and relationship counseling as a couple is not what's needed, but his own individual counseling is, for him, and for you, keep with the healing process, for yourself.
There is no hurry for you to follow him, until he proves himself, to himself, and gets a better idea that this is what he wants, and not just another leap from one person, to another so he doesn't have to be alone.
That fact is why you get a safe emotional distance from him, and stay there, so you don't let false hope trap you into someone who talks the talk, all of a sudden, but has yet to walk the walk.
He needs the space and time to do that, so let him have it, and speak no more of taking it slow or other nonsense at this time.
Giving him a chance when you know he isn't ready is setting you both up. And taking your time to let events play themselves out before you make a decision, gives YOU the option, and opportunity, and time, to get the FACTS.
If he is real, he will be better in 6 months. If he is not, well you are still healing. So stop justifying to yourself that taking him back is the right thing to do, because it may not be at this time.
I ask again, what's your hurry to put yourself back in this situation, before he has had a chance to PROVE he deserves your heart again?
Sit back and watch the actions, and see if the words match.