I’m so very sorry about your mum.
When you look back you will realise your DH’s timing is so selfish and heartless. Your DH has obviously been thinking about this for a while and knew it is bound to be agony for you to have to choose between your love for him and your desire for a family. And sure he doesn’t want to string you along, but really just weeks after your mum died, it is a terrible time to ask you to process the potential end of your marriage. You stuck with him through his cancer treatment and now he figures he wants to throw the no-kids bomb into your relationship? Bastard.
You know what? You do whatever you like. Don’t feel under any obligation to decide now. You can string HIM along for a bit. Focus on getting yourself into a better place. Focus on thinking about what would happen if you split up. If you want counselling with him, tell him he owes you, he has to come along. If he wants counselling together and you don’t, then do what YOU want.
On the face of it, I wouldn’t want this man walking alongside me through life.
You do honestly still have time to find another partner and have children. IME, that desire to start a family gets stronger and stronger, so if you want that, I would ask your DH to leave swiftly so you can put the pieces of your life back together.
Everything seems awful now, but in twelve months you could be in a very different position and this terrible time, this pain, will be behind you.
So sorry you are dealing with this.