I FINALLY beat the brain of Cthulhu, and lucky for me a meteor spawned right after I defeated it...
I mined out the entire thing.
Then I made the star cannon and used it to defeat the queen bee, I now have the witch doctor and can now make flasks of fire or poison
However in hardmode I'll be able to make ichor flasks.
Also after a few googled searches I figured out that it is actually possible to enter the dungeon without defeating skeletron, you just need to be able to tank hits from the eye of Cthulhu.
The dungeon guardians apply to the entity limit, meaning if you summon a boss who can spawn a lot of enemies (like the eye of Cthulhu) you can enter the dungeon, break a few pots for keys, and then open gold chests.
The only downside is that you can't get bones from enemies because they can't spawn, and you can't get the mechanic.
However you can get the muramasa meaning you can make the nights edge