I Am Taking 60 Mg Morphine Er After 5 Hrs

I am taking 60 mg morphine er after 5 hrs it slips off an I take a norco 10/325 and a 1 mg xanax I repeat this 3 times daily for cronic arthris. I an 66 hrs old have been on this for over 3 years it works real well I still work and can drive. I have worked the medication out to where I feel pretty good and can go without been impaired. My doctor retained and the new doctor is spouting out how taking xanax with this has raised my risk of heart attack by 4 fold so she cut me back to only 1 norco per day and trying to cut the xanax I n.c. Baptist hospital told me I would be in a wheel chair at the age of 30 i retaired from 2 jobs last being lawenforcement in which I done it all patrol etc. Is my meds that danger.