Severe insomnia since last two to three months. I got my blood tests done and my serum ferritin came out to be v low around 5. Are they related?

Insomnia . Low ferritin levels indicate that you are at a higher risk of having iron deficiency anemia. Although there is no link between iron deficiency and insomnia there is a relationship between restless leg syndrome and low iron levels. In restless leg syndrome patients feel a need to move their legs when in bed keeping them from sleeping. Check with your doctor to see if replacing iron is necessary.
Important finding. Insomnia may be associated with restless leg syndrome, and low ferritin correction may be very helpful. Also, wise to check vitamin d level and replenish if that is also low. Lastly, if the above fails to assist, an overnight sleep study may be of benefit.