Mesmerist Tank / Controller

I'm usually the Permanent GM, and I haven't played Pathfinder in about three years so I'm very rusty. I'm building a Grippli Mesmerist for my friend's campaign and I would like some input. I want to restrict my enemies and empower my allies, so I don't necessarily need to do a lot of damage. If I can be fully capable of supporting my allies, but still do decent damage, that would be optimal.

I'll post my build through the levels. It's still a Work In Progress, so I'm not 100% devoted to this build. I just want to nail it down so I can focus more on the fluff of my character.

Note: We rolled Heroic (2d6+6) stats straight down so I can't change my ability array other than in the normal stat upgrades.
Note 2: I convinced my GM to follow the advice set down in Feat Taxes in Pathfinder so if something seems off that's probably the reason.

Name: Quortle
Race: Grippli

Level 11
Mesmerist 10/Sorcerer (Fey, Tattooed) 1

STR - 13+1=14
DEX - 15+1=16
CON - 16
INT - 13
WIS - 13
CHA - 16

Race Traits:
Princely (Gain bonuses to social skills, swap net prof for rapier prof)
Jumper (Always running start to Acrobatics, replaces Camouflage)

Traits:
Reactionary
Adopted: Helpful (Halfling)

Skills:
+Bluff
+Perception
+Spellcraft
+Use Magic Device

Stats:
Initiative: +10
Casting DC: 21
Melee: +12/+7
AC: 29
Fort: +9
Refl: +13
Will: +17

I took Fey Sorcerer to up my spell DC. I haven't chosen my spells, but it'll be mostly battlefield control and buff/debuff.
My main concern is that I won't be hitting very often, and I won't be hitting very hard.
Not hitting often is kind of okay since that will force them to attack me instead of allies, and I have good survivability.

If possible, I'd like to:
Increase Spell DC
Increase to-hit/damage
Increase Fort
General Advice

Without sacrificing survivability/controller abilities.

Most of your strategy revolves around being in melee or close to it. You will likely run into the challenge of needing to make concentration checks to cast, which are generally harder for psychic casters.

I think you might get more mileage taking a level of fighter instead of a level of Fey Sorcerer. It will help your Fort Save, give you an extra BAB, grant you an extra feat, more HP, and save you two feats for armor proficiency. You could take spell focus and greater spell focus in place of the armor proficienies to have a better +2 DC to a wider range of spells (instead of just compulsions) and still have an extra feat left over to fill out your build (either mage's tattoo, a stare improvement feat, or something to boost your damage)

I'd also drop toughness. 16 base con on a d8 class will probably be sufficient for hit points. Greater Fortitude would be more useful or any of the feats above to round you out.

I think you might get more mileage taking a level of fighter instead of a level of Fey Sorcerer.

You raised a lot of good points here. I think I'm gonna take the 1st level in Fighter to get the most out of my HP. Would you recommend any archetypes?

I'd also drop toughness. 16 base con on a d8 class will probably be sufficient for hit points. Greater Fortitude would be more useful or any of the feats above to round you out.

Also an excellent point.