Yum-Tug the Lonely Ogre
At the time you had it all: a high GPA at Ogre University, an undergraduate adviser who wanted you to get a PhD in architecture, several job offers, a sexy ogre-magi girlfriend. But that seems like an eternity ago because now you are now trapped in a room of your own making, a cursed ring of regeneration on one hand and a blood drinking stirge waiting for you to pass out from blood loss.
The job was great when you first took it: all you needed to do was connect a group of previously existing tunnels with naturally occurring cave system. You hired your crew and had the project coming in under budget and ahead of time. The backer of the project, a greater basilisk, even went so far as to throw a party when the last tunnel joined the last cave. Little did you know that the party was an elaborate scheme to trap you and the secrets of the lair forever. A blow to the head closes your memory of the celebration: the next thing you remember is waking up in this completely sealed room.
Slipping the ring on was easy, but taking the ring off proved impossible. From what you have been able to piece together, the ring regenerates enough damage to keep you alive but no more. The stirge drinks your blood, you pass out, the ring restores you, the stirge drinks your blood, you pass out, and so on.
This pattern might be the next 50 years of your life since you come from a long-lived ogre family.