Okay, looking at your options the following spells heal sanity: Heal, Miracle, Limited Wish, Wish, and any of the 3 restoration spells. Your only option for Heal is a high level Runescarred Berserker. Miracle, wish and limited wish are obviously off limits. Your options for Lesser restoration are Champion of Gwynharwyf, Paladin, Knight of the Weave, Death Delver, Soldier of Light, Hunter of the Dead, Beloved of Valarian. None of them are full casters, but you'd have to check for spells forbidden under rule 2. Your options for Restoration are Champion of Gwynharwyf, Paladin, Knight of the Weave, Death Delver, Soldier of Light, Hunter of the Dead, Beloved of Valarian and Runescarred Berserker. Greater Restoration is off limits.
Mind Blank renders you immune to san loss for its duration. Your only option for it is Beguiler. Calm Emotions temporarily lets you ignore the effects of san loss. For it you'll need Bard, Savant, Celebrant of Sharess, Emissary of Barachiel.
Your best bet looks like a Bard, Beguiler, a Paladin, and a Barbarian who quickly Prestiges out. Virtually all of the PrC's above key off those classes (well they work with more, but these are the ones you are allowed). Without this your only options are alchemy (if the DM allows it), the Heal skill, or the optional Knowledge: Mental Therapy skill.
Your starting sanity is Wisdomx5, so go for anything buffing that stat.
I'd also peek at Incarnum and psionics to see if theres anything that would mimic the effect of those spells. Also look through the vestiges.