Oral cancers do not come and go, and usually do not change much once a lesion begins to develop except to get bigger, not bigger and smaller as you described. Yes there is a lymph node behind the angle of your mandible, but please remember that the lymph nodes job is to drain out all the toxins and cellular debris that come from everyday infections and more that your immune system is dealing with as a matter of regular daily life. That one of them gets swollen and sore is no big deal. As a matter of fact, cancer related nodes are PAINLESS, hard, and feel fixated in place, and you can't easy push them around like you can with a normal node. Soft nodes are normal and are Good.