How can i alleviate severe pain in tooth after filling?

Call your dentist: severe pain after a filling is not normal. The dentist who performed the fillings can best answer your question. If the filling was deep,perhaps you will need a root canal. Post op pain can also be from gum tissue, injections, etc. Sensitivity , especially to cold, is very common after fillings and can last a few weeks, gradually dissipating.

Visit your dentist: The decay was too close to the pulp and some bacteria had already managed to reach and damaged the nerve. Deep tooth decay that are close to the nerve is always a possible root canal therapy. Visit your dentist for examination, x-ray and treatment.

Yes- see dentist: Often the tooth in question can be sore right after a filling, but if it continues, have it checked. Could be high in bite or the nerve may have been compromised.