If you don't want to be with him, I would suggest texting him back, saying you've thought about it and there is no need for further discussion, wish him the best, and block him.
If you are somehow hoping that he commits to taking care of himself medically, commits to finding a job and finding motivation in life in general. Then text him back "I've thought about it and I've told you why this isn't working for me, if those things change in the future, and you are in a stable place, you may contact me then".
Either way, unless you want to fix him, and you don't need to try and do that to feel needed, there is nothing to be gained by talking today, this week, or this month.
If what you want is to fix him (I truly hope that is not what you are want)then you should talk to him later today.
Just my opinion, but I hate to see someone do something they don't want to do out of guilt.
M - 9 1/2 years 5/5/16 - Bomb drop - 3 week EA 10/31/16 - We sold house 01/10/18 - D Finalized
