Should I go to ER? Confused about Infection!

So, I have had a bad gum infection for about a month. Went to see my dentist shortly after it started, 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 behind in a very uncomfortable spot!!...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 and went and saw my dentist again.

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. Now, even my left eye feels kind of swollen and closes a lot sooner than my right, feels irritated and dry.

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) and causing weird side effects. 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.

[Gellia]

Hi,
Why wait?  Your symptoms could be many things and some not so good.
It may be to your  advantage to go to the ER and have it checked.  I am most concerned with the fact that you have weakness on one side of your face as these can be symptoms of impending stroke.  More than likely it's from infection swelling, though.

With that in mind, you may also need a different antibiotic.  Boils on the skin can also be from a Gram negative bacteria (Strep A) and amoxicillin works best for Gram +.  

To be on the safe said, if you still are exhibiting weakness on your left side with facial drooping, go to the ER and have it checked.  

Better to be safe that sorry.  

GOOD LUCK and do let us know how you are.
My very best to you,
Gellia