Titan normal is a bit special in that it gets easier as you let your DPS die.

The damage the tank takes is not really all that spectacular and most of your lost mp is due to DPS eating stuff they shouldn't. If both DPS die don't give up, the fight just got way easier! If the tank is decent they'll free you from gaols and if you're decent you had Regen on him so he'll live long enough!

Try your utmost to not cast Cure 2, it is an evil mp drain. Instead cast 2 Cure and make sure Regen is on the tank at all times. Before heart phase you only need to medica every 2-3 stomps, after it medica every time he stomps. Also medica the jumps / 2hour.
If a dps eats a weight of the land (circle on ground) use Cure to bring them up, not Cure 2.