Hi Teresa,
I am sorry you are going through this. I dont know much about MTX aside from what I have read. It appears that some of the symptoms that Brian is experiencing may by caused by the drug, but should be reported to your physician. http://www.drugs.com/sfx/methotrexate-side-effects.html
I dont think he should be working if he is experiencing the things he is. Also, I do know that 2 other posters here, Tom Rousell and suemarie's husband Neil had MTX, both palliative treatment. I dont think it is tolerated well. And I'm sorry if I missed something in your posts, but if he is this miserable with MTX, then why is he afraid of radiation?? I was 34 at diagnosis and went through radiation and chemo and tolerated it quite well, and I'm here to talk about it 7 years later. If he doesnt have radiation, he wont be so lucky. I agree with Suzanne that he may not be telling you the whole truth. Good luck to you and I hope you can convince him to seek further treatment.

SCC tonsil(left) with contralateral mets. Modified right neck disection August, 2002. 33 rads(62 gy)both sides of neck and 3 cycles cisplatin completed October 25, 2002. 34 yo at time of diagnosis