I had botox injections in my neck on 1/19. When I left a had a large knot at 1 of the injection sites. Any suggestions?

There is no problem with going for botox while you are on amoxicillin. It is a very common scenario because many botox patients are also on antibiotics for their acne or rosacea.

This should go away once the Botox goes away, which would be in about 3-4 months. Sorry to hear that you're not happy with your results, but this is not permanent.

Fillers are usually used rather than Botox to raise depressed scars to make them more even with the rest of your skin.

It takes 7-10 days to see Botox's full effects. I would monitor and, if sensations persist, see your injecting doctor.  Relaxation sensation is most commonly reported, but some patients have headaches or heaviness/tightness.

NYCBee,Based from your photos and your statement, you probably need a combination of filler to reduce the marionette lines and botox to relax the muscle. As for the botox, there are 2 main reasons shy it may not be working, the target muscle was not hit, or the dose may not be enough. 

You should see your doctor and let your injector know as well. This needs to be checked out as it may have been a result of your treatment, even if it is highly unusual. Best of luck.