Large Hard Knot Under Jaw

Help! I went to the dentist with an abscessed tooth 2 weeks ago. I have been on antibiotics now for 14 days. I have surgery scheduled to extract the tooth causing the problem; create a bridge; crown 4 teeth; and fill 2 cavities; however, this procedure will not be done for another 3 weeks! I have developed a large knot underneath my right jaw. It started out the size of a walnut but has grown to the size of a plum! Despite the rounds of antibiotics and living on anti-inflammatory medications,the knot is not going away. It is extremely sore to the touch and restricts the ability to open my mouth very wide at all (maybe only a quarter of an inch wide). I called my dentist about it last week and was told that I most likely would not see much relief until I have this procedure done. Not much was said to address the knot. I was not asked to come in and be seen. Is this normal? I am greatly concerned that the knot is growing. I would think the antibiotics would take care of it. What is causing this hard knot? Is there a specific over the counter medication that is better for easing the discomfort caused by the knot? My dentist prescribed hydrocodone, but it makes me sick. So we tried Ultram; it does not help at all. Am I just doomed to wait this out? I really like my dentist a lot. I don't really wish to start over with another one. Also, he performs sedation dentistry which is a MUST for me, as I have major anxiety/panic attacks about going to the dentist. Any help/advice would be appreciated.