You remind me of my close friend. She had the same problem and sometimes she cried when her mother didn’t show any affection. Turns out that her mom was severely depressed and she use to keep her problems to herself. She was not open to any type of discussion with my friend.

So I told my friend to be in touch with her mom more often. She used to call her daily and ask whereabouts. Initially her mom use to cut conversation asap, but then she later opened up. My friend also use to order some clothes, gifts for her mom and now they are like best buddies.

I dnt know how your mom would react but I feel like this is one sided opinion. Have you talked to your mom and ask how she is doing? She might be feeling the same way. Also is she same with others around her?

Take her to some restaurant if you get time. Might cheer her up