"The more time that passes by, the more he starts taking responsibility for his choices and actions."
Unless he actually seeks help or tries to figure out how to set things right rather than running away he is not taking responsibility. Taking responsibility is taking action.
"He took my wrist and sniffed it and said I smell amazing (lemon essential oil)."
I agree with Mr Bond Jenna. You just need to fine tune this a little bit and you will be better off. I think with a kick in the a$$ he will grow up. He sounds like what he is, a young guy needing to grow up.
Kind of weird.
IMHO, I would suggest to him that you deserve much more and that you totally agree with the breakup and that he does have alot to grow. And that you are not going to wait for him since he has shown no sign of actually doing so. Try being a little less 'nice' and throw in some attitude.
The thing is that you want him to want to do the work to make things better. But regardless of that, you keep getting yourself strong.