In monogamous relationship both tested negative for syphilis. 3 yrs later I test +. I'm a massage therapist, can I get this from touching clients?

Syphilis. Assuming "touching clients", means skin contact only, it will be very unusual to get syphilis from skin contact . Syphilis is sexually transmitted. If you are in a "monogamous relationship both tested negative for syphilis," then 3 yrs later you tested +. ----> Several things to consider. 1). Why was the test performed? 2). what type of syphilis test are you referring to? more info needed.
Not by massage. Massage is no risk for syphilis; you can't get it by massage, unless "touching" includes intercourse. Many syphilis blood tests are false positive, especially in persons at low risk. What is your RPR titer? Confirmatory test done and positive? In the US, syphilis is rare in heterosexuals, mostly in gay men. Continue working with your PCP, or health dept clinic or infectious disease specialist.
Not from touching. Consider repeating test, in unlikely event that one of your syphilis tests was false positive or false negative. Has your partner been truthful about having negative test 3 years ago or has he remained monogamous?