Methotrexate side effects getting me down......

Im wondering if anyone has had better luck?...... I've been on Methotrexate now for 15 months. initially, the side effects were fine and quite minor. Then they have been getting worse, with brain fog, nausea, tummy trouble, and extreme fatigue. I dread Wednesdays when I have to take the drug. I take it by injection pen, which is much better than taking it by the tablets. I don't really have Psoriasis, literally the occasional tiny patch on my elbows. I suffered for a very short time (3 months) with what felt like acute arthritis in every joint of my body, from top to toe. The Meth has gotten rid of this. Anyway, I have an appointment with my 'Rhumy' at the end of the month, and I wanted to see if i could be put onto something different? I know they will suggest Sulfasalazine, as that seems like the next step. But those side effects look just as bad. Has anyone jumped from Meth onto Biologics?.... I'm wondering if this might be possible?...... I'm almost considering weaning myself of the methotrexate, but obvs wouldn't without the correct advice..... Any suggestions are greatly appreciated. thanks!