Brain fog

I was diagnosed in May, and put on 200mg hydroxychloroquine and 20mg methotrexate injection once a week. I continued to have pain, so was upped to 400mg and 25mg. I started getting terrible brain fog, so cut it to 200mg H, but it has continued. I'm now down to 100mg H and 25mg M. My pain is mostly gone. The problem is, I can't think. I can't remember anything, and work is becoming difficult. I have no energy in the afternoons. Have others had this issue? I thought it was the H, but after cutting it, I'm beginning to think it is the M. Or is it just the arthritis? Any suggestions?