Antiobiotics not helping infection

So, I have had a bad gum infection for about a month. Went to see my dentist, they gave me Amoxicillin every 8 hours for 4 weeks. I've been taking it for three weeks now, and it doesn't seem to really have helped at all. The pain has gotten a little better, but the spot is still draining puss slightly and the same size. Another part of my mouth nearby is getting tender too. (This may be unrelated, but I find strange that it happened while already on antibiotics:  while on the amoxicillin, I get a abscess/boil/something on my butt (in the crack- ouch!)..I've never had one before in my life. It was pretty bad, but burst yesterday and started draining on its own.) At that point, I thought all would be okay, at least until I was done with the antibiotic treatment. Next, late last night I started to get a 'weird' feeling on the left side of my face. Hard to describe, like weakness or something, but I figured I just irritated something. However, today is seems to have gotten progressively worse, eg. I open my mouth wide and my lower lip on that side droops, pursing my lips to spit after brush my teeth and that side doesn't want to cooperate, my smile doesn't look the same, drinking out of Starbucks cup was really difficult because half my lip didn't want to seal around the opening correctly. I'm really concerned about this, that the infection might be really bad and/or spreading (the boil/whatever is was?? It's strange that I get one now while already on antibiotics). I don't seem to have a fever. I don't know at this point whether I should get immediate medical treatment and go to an ER? Or wait until tomorrow (sunday) and try to find a walk-in clinic/urgent care center that is open? Wait until Monday and talk to my dentist? Wait until Monday and see a clinic doctor? I'm very confused at to who to see about what and when. I have no insurance, so cost is important, but my health more so. Thank you to anyone who reads this and has any advice.