Pain in the back of my ankle while walking, mild pain when touch, when walking the pain is felt in my lower back calf.

Tendonitis likely. Sounds like achilles tendonitis if the pain originates from that thick tendon on your heel up to your calf. The most dangerous thing would be a blood clot in your leg, typically occurs after travel or sedentary lifestyle and you get swelling in leg. If calf is swollen and you recently traveled, see your doctor quickly. If tender on the tendon anti inflammatories would be best if stomach OK.