I am suffering from hypersomnia..... What should I do?

Sleepiness. Please do a sleep study to rule sleep apnea or sleep related disorders also rule out depresssion also rule out medical causes as well.
Sleep specialist. Hypersomnia has many causes: 1) sleep deprivation 2) other medical conditions 3) medications 4) primary sleep disorders. It is best to be seen by a sleep specialist.