Feeling dizzy and everything sounds funny in my head. Cause for concern? A few weeks ago I had a cold that made me lose my hearing in one ear for days

Anxiety, see a PCP. Anxiety symptoms are not a sign of illness, they are the mind's ability to produce the "flight or fight" response which gives rise to many physiological changes include chest pains, parasthesia, dry mouth, aphasia, tremor and sweating. Depending on the cause of your anxiety symptoms, your health care provider can recommend appropriate treatment.
Get it checked. The most likely scenario given what you have described is fluid in the space behind your eardrum. This is called a middle ear effusion and will frequently occur after a cold, affect the hearing, and also affect the balance. See your doctor.
Viral infection . Inasmuch as you had a cold (viral infection), the most likely cause of the hearing loss is what is now called sudden sensorineural hearing loss. This is a sudden loss of hearing (usually in one ear) that occurs over a period of 24-72 hours. The treatment is either oral steroids or injection of steroids into middle ear. You are lucky that the hearing returned.