I think Mike J put it rather succinctly .... I would tell him just that.

You're willing to wait but not willing to put your entire life on hold for 2 years, that you're not in a hurry to meet someone however 'You should move forward when you are ready for it, if it's with him once he is done with is recovery great, if it's with someone else that is fine too.'

And its fine for him as well. There is no guarantee he won't meet someone during his recovery, whether he plans or expects it, or not. The swing moves both ways.

Take care.