Is it sinus, migraine, vertigo, or something else when you are congested, with headache and a bit dizzy?

Sinusitis. Sinusitis is characterized by most of your symptoms. It can be acute or chronic. Consult your physician for treatment.
See you doctor. Both headache and dizziness can be signs of something serious and should be evaluated by a professional. I can't answer further without more information such as where is the headache located, have you had headaches in the past, do you suffer from cluster headache, etc. In sum, see you doctor.