It sounds like you have the right idea, but here's some tips or suggestions. Buff potions definitely help, and also you will want to make sure you are using the Greater Health Potions, not the lesser ones of course.
If you haven't done so already, I suggest you try making a very long bridge. It doesn't have to be completely flat but at least enough that it's very easily traverse-able and you won't get stuck somewhere by accident or fall into lava. You'll want to focus more on the battle than trying to get around down there.
My weapon of choice for this battle would be one of the flails (Or any big Sword such as Night's Edge) for the numerous mini enemies attached to the wall. Flails take them out easily and quite efficiently since you can hit almost all of them at once. Once those are all done for, this is when switching to the minishark is a good idea. It puts out lots of damage very quickly, obviously, plus the bonus ability to save ammo every-time you shoot it. If you have the Goblin Tinkerer I suggest you put some money in reforging weapons for better stats, not necessary but makes a very noticeable impact when you get a good one.
As for your accessories, you might want rocket/specter boots to get around easier; a cobalt/obsidian shield so you aren't knocked around or into lava, and also in case there any exposed hellstone you could accidentally walk onto; and a Band of Regeneration to quickly recover lost HP. The other two are up to your preference really. I would also suggest reforging these to try and get the Warding prefix (+4 defense). Again not necessary but it will help tremendously in the long run. Especially since having 5 warding accessories means +20 defense.
You can also try to focus on magic items to defeat it. A Vilethorn also makes quick work of the smaller enemies while a space gun (with full meteor armor) will constantly damage the actual Wall without ever using mana. A Demon Scythe is definitely my favorite weapon to use against it though. It will hit everything it passes through, and while it's "charging up", the boss can be directly over it getting hit 3-5 times guaranteed. The only problem is how hard is can sometimes be to find.
If you do decide to use magic items make sure you have a full 200 Max Mana and some Mana potions as well. Restoration potions can also help here as they give back both mana and HP but will give the "Potion Sickness" debuff on use, unlike regular Mana potions. You can also get a Mana Flower to equip. This will automatically use mana potions for you so that you won't have to worry about how much mana you currently have.
Once you do manage to defeat it the first time, beating it again will just get easier since you will have access to higher tier items.
The Pwnhammer should drop every time you kill the WoF. If it hasn't, you've encountered a bug, try validating local files with Steam to see if that fixes it. Otherwise, you can use an inventory editor like TerrariaViewer or a world editor like TEdit to give yourself the Pwnhammer.
Best Answer
The Bee's Knees is highly recommended against the Wall of Flesh.
Firstly the initial damage is about the same, slightly higher for the Molten Fury, with one extra damage and the On Fire! debuff, so there isn't too much difference with just the initial shot.
However the Bees Knees is strong especially against the Wall of Flesh because after it hits it's an enemy it will pierce it and the bees can cause damage to whatever's behind it. This is perfect for the Wall of Flesh because it can be hard to cause damage to the Wall as The Hungry are in the way, making it difficult. But with The Bee's Knees, you can do damage to the Wall while still taking out the Hungry.
Also another bonus of the Bee's Knees is that if you miss, which is quite easy to do when you're running for your life from a giant wall of flesh, the Bee's Knees 'arrow' can ricochet off the wall (breaking into five separate bees like when it pierces a target) and come back and possibly do damage again. This is far superior to the Molten Fury, because if you miss with that you do zero damage, and you'll likely miss many times during this fight.