How Do I Tell If I Have Tendonitis Of My

How do I tell if I have tendonitis of my heel? I have swelling of the foot, ankle and terrible pain up the back of the heel into my leg with discoloration on the medial ankle.. had a foot turning injury and it has gotten worse as I walk on it.. been gong on two weeks now . Can barely wear shoes as the pressure against my foot causes even more pain. IBP/ ice/ heat help but it keeps coming back.