I had a pimple on lower lip and it was bugging me so I popped it, over night lip became swelled and I'm not sure if it has turned into cold sore or not, lip appears swollen with sore filled with fluid and white head. Feels irritated?

Abscess? Although it may just be swelling from the trauma of "popping" it (the lips are very sensitive), it may have developed into an abscess. It should certainly be evaluated by MD. It may need antibiotics or to be drained. Most urgent care clinics can take care of this, as well as primary care offices, though they may shy at draining since it's on your lip.