Ive had a dry cough for a couple weeks now, post nasal drip, runny nose, sore throat every now and then, i think im starting to develop a fever and im getting lightheaded/feeling faint when i stand and walk & slight body aches. do i have covid19?

Hard to guess.: You have some of the symptoms of cold , flu and covid19 . Also you appear to be dehydrated. But you are young and no mention of any underlying medical condition. So, i think you are not vulnerable. Drink at least 6 cups of water a day. Probably need self isolation for 2 weeks and to be tested in mean time for covid19 if you develop breathing problem. Contact to your doctor for a guidance.