Muscle pains, twitching , balance problems, no diagnosis HELP!

Hi, I'm new on here but I have been reading loads of posts and hope I have posted in the right place.

I'm 25 yr male and very rarely have anything wrong with me. Oct ‘08 I started running and doing weights 5 days a week and rested at the weekend. I ate real healthy and was feeling great.

Feb ‘09 I started getting strange sensations in my thigh and arm muscles like my muscles were crawling/moving really slowly but didn't cause any pain. The next week I started getting throbbing pains which would move all round my arms and legs and felt like my muscles and bones. I tried to ignore them and rested from any exercise but they didn't go away and I started to get pretty worried.

I saw my doctor several times and she thought it was a virus and the pains would go. They didn't go even though I had two weeks off work resting.

A month ago I started getting strong muscle twitches in my thighs and arms, my face twitches too but only slightly. I have also got really forgetful and can't organise things like I used to.

My vision has also changed and things look surreal and if I look at a wall or floor for a few seconds it starts to move which freaks me out.

I have also had problems with balance and walking although this hasn't affected my daily life yet.

I was referred to a neurologist who gave me a basic neurological exam (perfect pass) and also ran a load of blood tests which seem to all be normal. He referred me for a MRI of my head and neck and I am waiting on the results.

POSSIBLE CAUSES:
Along with the possibility of a load of neurological diseases, I have come up with these so far,

1) Mould and damp on one of the walls in my bedroom and was wondering about some kind of mould poisoning? but even if I'm not in there I still have the pains and twitching etc.
2)Some kind of allergy?
3)Brain Tumour!

It's really taking its toll on me mentally and I can't help but worry about some of the awful things like ALS and MS. Some days I think I’m feeling better and don't get much pain but then the next day all the pains and twitching will come back with no apparent reason.

Please, if you have any suggestions about the possible causes or can help me get a few possible causes straight I would be very grateful.

Thanks