I thought about that before I made the post (I’ve played way too much in the Realms 
), but then i realized that the OP didn’t actually say that the campaign is set in the Realms. He said that the DM was using the Realms gods (as well as the gods in the “core pantheon” in the 3.5 books).
It’s not an exact match, but you might have the best shot at getting your DM to let you take Finder as your character’s god and add the Retribution domain to his portfolio. Finder’s very new, as gods go, so his domains could still reasonably be in flux, and he has something of a vengeful bent at times. He also has Charm and Renewal domains, either of which might be useful or appropriate for the character’s goals. (Charm for gathering allies, and Renewal for raising a new kingdom from the ashes of the old.)
His worshipers are mostly bardic types, but there’s no reason your guy couldn’t have fallen in with a bunch of bards and performers–maybe they smuggled him out of the area? Also, if your fallen kingdom was known for being supportive of the arts (say, home to a major bardic college or something), Finder might have taken its destruction rather personally.
He’s Chaotic Neutral, but you could certainly play a Chaotic Good cleric. (In fact, if I recall his top human priest correctly, the guy is almost certainly Chaotic Good.)
The real world Norse mythology has the perfect deity for this, he just hasn’t been included any D&D pantheon for some reason. His name is Vidarr and he is the son of Odin and a Jotun named Gridr, which means you don’t have to bring in the Norse pantheon, just tie him in to the racial panteon of the giants who already include figures from norse mythology (Surtr and Thyrm).
How is he ascociated with retribution and vengeance? Well in norse myth, when the Ragnarok comes and Fenrir (also reference in core D&D’s Epic Level Handbook) eats Odin, who do you think is the one to avenge his death? Thor? Sorry he’s busy fighting Jormungandr, the world serpent. How about Tyr, the god of war, who was the only god not afraid to sacrifice his own hand to chain Fenrir in the first place? Nope, he’s busy fighting another big bad wolf named Garm that basically had the same job as Cerberus before the Ragnarok. Frey, Heimdall? They’re both busy fighting Surtr and Loki respectively. No it is Vidarr who ends up fighting Fenrir.
How does this go? Well he basically just stands on Fenrir’s lower jaw, grabs hold of the upper jaw… and rips Fenrir apart, literally. Furthermore, unlike those other gods I mentioned above, not only does he survive his famous fight, but he survives the rest of the ragnarok as well (which presumably includes his own clashes with Surtr who also survived his fight) and completely unscathed to boot. Thus you can just say that this D&D world is set post Ragnarok to explain why you don’t hear about the other norse gods.
Now for Vidarr’s important game information:
Vidarr
the Silent God, Fenrislayer, Vidarr the Silent
Intermediate Deity
Symbol: A wolf skull with a broken jaw
Home Plane: Ysgard
Alignment: Chaotic Good
Portfolio: Survival, Righteous Vengence, Good Giants
Worshippers: Barbarians, Fighters, Good Giants, and those seeking vengeance
Domains: Endurance, Retribution, Strength (Chaos, Good, Wrath)
Favoured Weapon: Waraxe
The Endurance domain can be found in the Book of Exhaulted Deeds, as can one version of the Wrath domain (another is presented in the Spell Compendium, and either would make a good domain option). It is this Endurance domain that I would recommend for a vengeance seeking healer. It’s not as good a fit as the Healing domain, but the ability to reduce the damage you and your allies take, is very helpful to a healer, and the extra hit points granted by the constitution boosts from spells and the domain power fit well with a healer. Even if the only actual healing spell on the list is one that only works on nonlethal damage.
His titles pertaining to silence are due to the fact that this god does not speak, and are further proof of his connection to revenge, since he will not speak until all wrongs against him, his family, friends, and followers, have been avenged.
Maybe he should worship one of those gods who are into raising things from the dead…
If retribution is what you want, Tyr is the epitome of it. He’s LG, so you can be CG and still fit in the ethos. Of course, as a Chaotic character, you’ll have to come up with a lot of creativity in order to stay within legal bounds.
Indeed. I opened this thread, thinking, “I could probably offer some guidance”, and then saw that I had already done so, exactly a year ago. 
You could always worship me! That’s what my character did, a rogue/cleric/arcane-trickster also named ‘Autolycus.’ He’s not so big on the retribution part though…
Banjo the clown!
Damn, ninja’ed by one frickin’ minute…
Think he’s Neutral Good tho. 