Warning: Wall of Opinion incoming. I vastly prefer Wizards to Sorcerers.
Wizard 2
Be a conjuration specialist, give up Necromancy and Evocation.
Str: 9
Dex: 13
Con: 15
Int: 17
Wis: 10
Cha: 9
Max spellcraft, concentration, and knowledge skills appropriate to the campaign.
Take Sleep, Enlarge Person, Silent Image, Mage Armor, Grease, and Obscuring Mist as your spells.
Sleep takes care of groups of mooks. Obscuring Mist makes ranged enemies come to you (Cast it and instruct the party to step back behind it). Grease makes things flat-footed for rogues to kill (it forces you to make balance checks, if you attempt a Balance check without 5 or more ranks in Balance you are flat-footed). Enlarge Person lets your melee's kill things better. and Mage Armor keeps you alive. Silent Image is well... limted to your imagination. They only get a will save if they interact with it. Silent Image of a grease spell in front of smart enemies for example....
EDIT: And ditto on the light crossbow.
For feats consider Toughness or Improved Initiative.
Don't forget to Scribe scrolls of your unused spells each night, to help you last over more encounters the next day. A level 1 spell scroll costs you only 2 xp and 50 gp. Half that if you scribe it with a caster level of 1 instead of two.
That should keep you useful regardless of the situation.
Guard. Your spellbook. With. Your life. (and your party members lives, if applicable)
And take a look at some of the most excellent caster guides we have here for your future games.