My knees hurt so bad from sitting at work desk. its gotten to the point where they hurt and cramp constantly. nothing is relieving it. what else can i do? i stretch frequently during the 8-9 hours?

Consider getting a standing desk. That will give you the option to stand intermittently while working and not have to leave your workstation. For healthy diet: http://www.choosemyplate.gov/., exercise 30 minutes/day, drink enough water daily so your urine is mostly colorless, have safe sex, no tobacco alcohol weed or street drugs. Get HPV and Covid vaccines. Wish you good health!

Check the knees: if warm or if you feel crepitus (crunching) under the knee cap, see rheumatologist or orthopedist. Can do straight leg strengthing exercises or wear copper elastic hose. Or can try a topical antirheumtic: diclofenac 3% (Voltaren gel). If overweight get started on weight reduction; either way avoid carbs and saturated fats. Some people find that glucosamine sulfate helps.