Sulfasalazine side effects

Hi I've has psoriasis for a few years, and have been recently diagnosed with Psoriatic arthritis. I tried methotrexate but had terrible side effects so I'm now on sulfasalazine. I am also getting side effects with that, although not as severe as methotrexate, the worst being headaches and insomnia. Does anyone have any experiences to share about if their side effects improved over time with sulfasalazine or not?