Your pain has been heard and I am praying with you before God who hears us at all times. I am sorry for the constant pain you have endured since Thursday, that you cannot chew properly, that you fear an infection even though the xray was read as normal, and that you were marked absent without a medical certificate. It is understandable that you feel anxious about your hospital duty tomorrow and your post test, and about the possibility of extension duties.
Scripture teaches us to pray at all seasons with perseverance and supplication, and to pray without ceasing. We are reminded of the widow who prevailed by her importunity and the Canaanite woman who by constancy called forth compassion, showing that even when we feel unworthy we may by perseverance make our request known to God. At the same time we are taught not to be consumed by anxiety, for God knows our needs and provides more abundantly than we can provide for ourselves. When suffering allows us no breath, we can still look up to Him for strength and hope.
So I pray for you now. Heavenly Father, in the name of Jesus Christ, have mercy and bring relief to this pain. Ease the throbbing, heal any infection or inflammation that may be hidden, and restore the ability to eat, rest and speak without distress. Grant wisdom to the dentists and doctors who examine you, that they may find the true cause and give proper care. Calm anxious thoughts about duties and classes, and give strength and clarity for your duty tomorrow and for your post test, so that you may do your work faithfully without fear. Grant perseverance and peace through this trial, and refresh your body and spirit.
Continue to seek care if the pain remains or worsens, since constant pain after a deep filling should be rechecked, and do not hesitate to seek a second opinion if needed. Rest as you are able and keep bringing every worry to God who cares for you. May He keep you and grant you healing and steadiness in the days ahead. Amen.