Ok, my setup: My guitar/mic is plugged into a mixing board which is connected via the headphone output to my computers mic input, works like a charm. I use FL Studio 7 XXL Producer Edition for all my recording and sound editing. Problem is I have been unable to find a decent distortion VST plugin, best I've found is juicy77 which, even making use of an equalizer plugin, still sounds bland and dry. What I want is to get that extra extra smooth fuzzy treble & bass & no middle distortion, listen to the first few seconds of I Am Hated by Slipknot if you don't know what I mean. Some people say I should just buy a really good metal amp or pedal but I can neither afford nor be bothered to go shopping for either at the moment.

Hope you guys can help
Honestly? There is really nothing better than a good amp and/or distortion pedal.
But surely it wouldn't be too hard to find something that can do the exact same thing as said amp/pedal but using my computer as the processor and my headphones as the speaker? Because really all an amp is, is a bit of programming connected to a speaker.
Sorry, but if that were the case, SS amps would have outperformed Tubes years ago.
You can get some decent ones. I'm not very knowledgable on the subject, but you could try the virtual pedalboard that someone on this forum made and offers for free. Search the R&R forum for it.
There is poetry in despair.
Because really all an amp is, is a bit of programming connected to a speaker.

And the way that amp physically interacts with itself, your guitars signal, the speaker, the cables, the cabinet, the air around it, are all what makes a guitar tone what it is. Not to mention the characteristics of the microphone, preamps, and converters used to get the signal down to 1s and 0s.

There is no physical interaction in computer code, only attempts to model the non-physical alterations applied to a soundwave when distortion is engaged.

They are 2 different things, don't expect them to sound the same.
I've heard good things come out of Izotope's Trash. It gives a ton of flexibility that most pedals won't do without trickery. You can decide for yourself. Still, few things come close to a 5105, JCM800, or Dual/Triple Rectifier.