What Causes Swelling In Cheek After Taking Keflex For Swollen Lymph Node?

Monday March 9th I was laying in bed and an instant burning/heat sensation formed in my bikini line, was strong and persisted for about a min so I stood up, lookes and there was a ball that had formes under my skin. Wednesday the Dr told me it was a swollen lymphoid noid and put me on keflex. Saturday night I started forming a blister on the inside of my right cheek and by Sunday night a hard ball had formed on my jaw line by the mouth. Woke up Monday the 16th and the whole right side of my face was swollen. Went to the Dr, he put me on Augmentin, and told to go to the dentist asap. By Monday afternoon I could feel the swelling into my neck and back of my heahead, as well a blister started to form on the inner ledt side of my mouth as well as the hard ball the outside on my jaw line. I went to the ER, they said possible abscess in my tooth, tried to drain my cheek but nothing came out. Tuesday the 17th I went to dentist and they did x-rays but couldn t find a infection anywhere and I have no pain on my teeth, really no pain at all. The dentist put me back on keflex, 500 mg 3tx a day, and said come back in a week for additional x-rays to see if he can find anything. It is now Wednesday the 18th, the swelling is on both sides of my face but has gone down some. I started getting tingling in my left arm 2 hrs ago and now both of my lower legs are tingling.....my dr, er, and dentist said my lymphoid swelling and my mouth dont pertain but worried they do and something more serious is going on. Does any of this seem familiar and at what point do I go back to the ER??? And input or advice would be great. ...