I'm so sorry to hear about your situation. Is there anyway that your rhuemy would see you on a sliding scale and maybe give you some samples? I also take the MTX and it is fairly inexpensive even without our copay. Here in our area we have an organization that actually gives out free prescription cards and with these cards, clients can gain discounts on most medications, most being around $7.00. I'm not sure where you are located, but perhaps there is something like this where you live.
Chances are if you have been with your rheumy from the beginning of your diagnosis, he or she will work with you as much as possible, so that you don't have to go without your meds, especially if you are on the MTX. I don't know if this helps any but my pain pills without insurance are only 15 dollars so they come pretty cheap, and they are the darvocets. I fill my prescriptions at Wal Greens.
The main concern is that you are not in a great deal of pain, and maybe someone else will come along with some over the counter ideas for help. I'm sorry I don't have any of those
I wish you the best!