Toothache is worse after going to the dentist...what should I do?

I went to a donated dental care because I'm a poor college student who has had a toothache going on 3 months (sensitive to cold, almost constant aching). Anyhow the dentist filled two cavities but said one was very deep...now that one feels worse than before and it's been two days. Do I need a root canal? Should I just get it pulled? It's my very back molar on the top. Thanks.
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well i just had the same thing done on monday a deep filling and yes it hurts but its only because it was so deep i was told from my doctor to keep an eye on it because its going to take a few days (or maybe a week or so) he said to take ibuprofen for the pain. he also said that if the tooth was that bad that it would be reacting to the filling as well and you know for sure because the pain would never go away and then they would have to do a root canal. If its the molar it may just be able to remove because you really don't need your molars. I hope that helps and that your pain will go away. Ps iam taking 2 in half ibuprofen every 4-6 hours or as needed but dont OD on them.
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