I took methotrexate at the dose you are on. I had all the side effects you mention. After being on it a month I had a doctor's appointment and told him about the side effects and the fact that I felt like I had a mild urinary tract infection ever since I started it. He immediately lowered the dose to 4 pills for a total of 10 mg. He said that 10 mg is the lowest effective dose and that's the lowest he could go. The side effects got better and no UTI symptoms.