Old abcessd tooth

This morning I woke up and noticed my right cheek at the jaw was puffy. No real pain to speak of but swollen and feels a bit tender.
About 3 years ago I had the first molar on the bottom right abcess (abscess)....pain, dainage, all the usual stuff. I didn't have dental insurance (nor do I now) so I went to the ER they gave me antibiotics and said see a dentist.
So the blackened, sore, (sometimes odd smell/tasting) tooth remains to date. I fear it is re-abcessing (if possible) or is the gunk from the old tooth seeping into my cheek; which I have read is possible.
So I guess what I'm asking for is what could be making my cheek swollen? Can the same tooth abcess (abscess) again? Can having a former abcessed tooth cause the swelling? Can it be bacteria from the old tooth?
Most importantly, do I have anything major to worry about?...besides the horror stories about blood poisoning, bacteria traveling to my brain/heart.

[Gellia]

Hi,
You will need to see a dentist, and very soon.  The old infection has flared up again.  When the ER told you to see a dentist at the first infection it was to get rid of the cause of the first infection.  Usually this a build of plaque around the tooth that allows bacteria to reach the root area and bone.
Infection on the inside of the tooth requires root canal.

When the infection comes back after this length of time it's just been brewing there.  You HAVE to get to a dentist and get an xray to see how much bone is left holding in that tooth and the integrity of the teeth neighboring it.

Please don't wait.  I did and lost four teeth because I waited too long.  The horror stories will also include having the tooth and the neighboring teeth just fall out from bone loss due to infection.

Please make that appt ASAP.  You say it's already been three years since that first infection.  Time will grow short for the life of those teeth without dental help.

Hope this helps.
My very best to you,
Gellia