My first time was rough as well. Brayflox is quite a good teaching dungeon for healers. First, your job is to keep people alive -not at full health. Damage Dealers can be ignored until they are status effected or at half health. Use ethers as soon as you can. The timer is painful. As others suggested, esuna saves magic power. Also, communicate. Tell your party what they are doing that strains your magic points. Best of luck!