Could my adrenals and thyroid levels being low affect my high iron but low RBC levels?

No. Unrelated, if RBCs are extremely low, not just marginally low, better see a hematologist for evaluation and management, good luck .
High iron. Probably not. If you have been having low RBC levels you may have been given high doses of iron. If the low RBC is not iron deficiency anemia, then iron will not help. High iron in blood can cause many problems including accumulation in the liver causing hemachromatosis.