Extremely high VPS shared memory

Hi, I'm Michael and I'm a novice here – so … need help

Can any one explain this extremely high value of shared memory after the "free -m" command?
The values ​​of "shared memory" exceed 6 to 10 times my RAM and destroy my site every two or three days for 3 to 4 hours.
I have no idea where the "shared memory" comes from in the VPS server … but no matter …
My VPS hosting provider said: "It looks like you need more RAM" and of course, they want to duplicate my fees … so, this answer has kind of surprised me, because my site usually works perfectly at "rush hour". consumes about 30-35 percent of RAM …

Please any help and answer.