Yes, you probably had a fever and weak from the cold/flu. All the lightheaded and dizziness was just from working out while being sick.
common cold and Flu are caused by virus which may cause fever, malaise and weakness.
Take proper rest, eat healthy and continue work outs after couple of days. Take care!
i forgot to mention that i started to feel tired and lighteaded/dizzy a couple minutes AFTER i stopped doing the cardio