In need of right and kind words of comfort for grieving partner

My partner's mom died last month and it's been hard for him ever since. It's going to be Christmas and New Year soon, the once happy house has now became quite. I am heartbroken for my partner and for aunt (she was a bit close with me) No one will prepare any foods, desserts for occasions anymore. It won't be the same. Her birthday is also Next Year January, even I'm having a hard time trying to express the words to say to my partner for it. He is super devastated and in denial of the situation. He just couldn't take it (he is a mama's boy)

Any advice on what I could say to him? I've said some comforting ones already but I think I'm looking for a more heartfelt message.Also, quotations or sayings about getting through grief that helped you in the long run would help, I would love to read some of it!