Swollen lymph nodes in my neck and 1 on my collar bone and fevers for 3 years was diagnosis with low iron should i still be worried out cancer?

Lymphnodes: Lymphnodes should be monitored aggressively with your symptoms, especially with some in the collar bone area. you may benefit form scanning and even a biopsy to be safe. Best wishes.

Possibly: Swollen lymph nodes and fevers for that length of time, especially with anemia/low iron, is concerning either for chronic infection, a chronic inflammatory condition, or cancer. The CT scan your profile mentions is probably a good idea and you should think about seeing an oncologist, infectious disease doctor, or rheumatologist if you have not already.

Specialist: If you have fevers of unknown origin for three years and persistent enlarged lymph nodes, you are recommended to see a specialist in infectious diseases or oncologist. Lymphoma and autoimmune disease are possible causes and a lymph node biopsy may be needed.

Recommend evaluation: I'm not aware of iron deficiency associated with swollen nodes. Nodes which are larger than 1-2 cm, firm or hard, and fixed (not freely movable) can be concerning especially if persisting for longer than a couple weeks without resolving. Lymph nodes enlarged around collar bone especially and warrant further evaluation like FNA. Iron deficiency is linked to anemia, fatigue and restless legs.