Hypothyroidism, with joint pain, stiff feet, tingeling fingers, bone pain memory issues dizzy spells and sometimes slurred speech . what gives?

Inflammation?: Sounds like a multi systemic issue. Could be inflammation or something else. Must look for cause. Sometimes food sensitivities can be a factor. Sometimes infection such as lyme. Environmental toxicity also contributes.

Levels normal?: If your thyroid levels are normal on brand name T4 replacement, then look to other possible causes for your symptoms.