Ok, you've made a few amateur mistakes, but thats ok. We were all amateurs once, and critisism is how we grow. Now, the first thing we here on the boards need to know, is what books you have available. Its common place here to throw out a build using a dozen or more books, some more, some less. It all depends on where the classes, feats, spells, and features are that we need to put together to make something servicable. So, kindly let us know the extent of your library, or indicate that "anything goes" and we'll be on our way.
OK, your build...where to start. Since its already been mentioned, Vow of Poverty, and Sacred Vows in general. They are bad. Like, terribly bad. Terribad even. Why are they bad? First of all, they require your character to be Exalted, the most strict of goodly good. If you character ceases to be Exalted, you lose all of your Exalted feats. Now, depending on your DM, you might have an enjoyable experience exploring the extremes of Lawful Good, or you might fall for checking out that lady wizards behind while she's crossing the street. Its SOOO subjective to DM control, above and beyond anything else, that its a huge risk. Mechanically, VoP gives you some bonuses to your stats, but if you consider the net value of all of your bonuses and abilities and features and whatnot, you are better off 999/1000 times having magic items. And that 1/1000 time, you'd probably break even...maybe. Well, this isn't that 1/1000 time, and you've got WAY too much to lose giving up magic items.
So, what next. How about Dragon Disciple. Its widely regarded as one of the worst PrCs invented. Why? Because of lots of reasons. First of all, its a melee class, but only has 3/4 BAB. This is bad. This is the primary failing of the monk class as well. 3/4 BAB is not good, because it lowers how much you are allowed to PA for by a lot. This is bad, becacuse PAing is good. Moving along, DD requires casting to get into, but doesn't advance casting. It gives a couple of bonus spells/day, but really, if you already have 4 1st level spells memorized, do you really need 5? or 6? Your build is technically illegal, since DD requires a spontaneous caster, which the wizard is not. Sorcerer would have the desired results you are looking for, but a class called Duskblade from PHBII is better. Its an int based spontaneous caster with full BAB. But then again, you are going into DD, which is a bad idea to start with. Also, there is very little synergy in the class features. You get a breath weapon, but its really weak for the level you get it, and its only useable once per day. Thats crappy. The wings are kind of cool, but come way late to really be useful in mid levels, so you might as well not have them. Bite and Claw attacks are pretty much a joke, and its hard to hold a weapon and still be able to use them. So, maybe think of a different PrC to head into. Pious Templar is a good one from Complete Warrior. Its kind of a paladin lite, devoted to whatever god you want. Full BAB, gives bonus feats, DR, and a bit of smitage, its a lot of fun. Regardless, figure out what you want to do that's not DD, because DD is not good.
And now on to feats. You have the Whirlwind Attack chain. This is bad. Especially the fact that you are finishing it at level 20. At level 20, your character should have 4 attacks, maybe more in certain circumstances. Its better to focus all 4 attacks on something and kill it, than spread your damage around. Dead foes do exactly 0 damage to you, while foes with even 1 hp level deal full damage. Plus, if you get yourself in a situation where you are completely surrounded to the point where WW Attack matters, then you've done something wrong tactically. Back into a corner or something so you don't get surrounded. Utilize allies in a back-to-back formation if you are really that swarmed. Hope your party members have crowd control spells and abilities to help funnel some of the swarm thats mobbing you. Regardless, WW Attack is a waste of feats. Combat Expertese is really not very good. Dodge is even worse. Mobility is completely replaced by a few skill points, and the AC it grants probably won't save you otherwise, and Spring Attack nerfs your full attack down to one hit. Hit more, and stuff dies. Hit and run away, and that stuff will walk over and eat your friends. So, WWA requires 5 bad feats to get, including WW attack. You'd be better off spending them on other things. I'll get to that when you specify what books you want to use.
Now, you want a character that can tank? Kind of like the paladin idea? Try this:
[spoiler]
Human Paladin5/Fighter2/Divine Crusader1/Ordained Champion4/Divine Crusader +8
Pal 1 - Law Devotion, Improved Toughness
Pal 2 -
Pal 3 - Knowledge Devotion (CChamp)
Pal 4 - Holy Shield (give up Pally casting, ACF from PHBII)
Pal 5 - (Charging Smite ACF from PHBII)
Ftr 1 - Power Attack (F, PHB) Divine Might (CW)
Ftr 2 - Weapon Focus: Longsword (F, PHB)
DC 1 -
DC 2 - Awesome Smite (CChamp)
OC 1-
OC 2-
OC 3- Holy Warrior (Reserve Feat, CChamp)
OC 4 -
DC 3 -
DC 4 - Practiced Spellcaster (Divine Crusader) (CDivine)
DC 5 -
DC 6 -
DC 7 - Extra Turning (PHB)
DC 8 -
DC 9 - (no spell progression, but you do get +1 CL)
[/spoiler]
Build uses primarily PHBII, Complete Divine and Complete Champion, and Complete Warrior. The build starts off as a sword + shield build. As soon as possible though, you'll want to try to get an animated shield, perferably by about level 7. That'll allow you to 2hand your sword, while still getting the benefit of the shield. Cha is actually your prefered stat, though str is right behind it, with con following third and then everything else. Dex and Int should be your lowest stats, if you can pick. This build gets a lot of defenses from Law Devotion and Holy Shield, which it can easily turn to offense as the need comes, with Divine Might, Power Attack, the Ordained Champion's Smite, the Holy Warrior feat, and Knowledge Devotion. Lots going on, but its good stuff. Divine Crusader gets full 9th level casting in 1 domain. Which domain you pick depends on how you want to play. I like the Travel Domain, for goodies like Fly and Teleport. Ordained Champ gives you War, so you have no choice about that.
So, if you are interested, take a look through that build, look up the feats and classes in their respective books. This build is much more solid than your DD one, because it can defend itself against attacks and spells while still maintaining decent offensive capabilities. Its also very focused.