Thanks for putting up your question on Just Answer.
The symptoms you are reporting could be just inflammation of the pulp
of the tooth(pulpitis
However, if you experience severe pain
on biting, then there are chances that there is an infection.Also, if there a boil on the gums near the tooth with puss coming out of it, we can safely assume that it is an infection.
Other than going to a dental school(which is a very good option), here are some other avenues of affordable dental treatment:
1.Try to contact the local dental society in your area and see if there are any charitable organizations or foundations that will do your treatment for a reduced fee.
You can find the contact information of your local dental society by visiting :http://www.ada.org/ada/organizations/local.asp
2.Here is a website that lists dental offices that offer free and discounted clinics all across the country. Search for one in your area. Read each listing carefully as restrictions apply to some of the listed outlets.http://www.freemedicalcamps.com/
Hope this answers your question. Feel free to contact me again for more information.
I wish you a speedy recovery !!!
If my answer has helped you, please click on the *ACCEPT* button and give me *POSITIVE FEEDBACK*.
A * BONUS* will be highly appreciated. This tells me that my advice was indeed beneficial.