Talk to Gastroenterologist on Chronic Constipation

I have chronic constipation issues for more than 20 years and with continues use of Laxatives my constipation is getting worse. Ten years ago with a very reputable bowel hospital many tests the main consultant informed that my constipation is ediophatic but one test did suggest evacuation disorder. I went through biofeedback sessions for few months but not good outcome. The consultant suggested to take up to 6 movicol Sachets if required but my main constipation medicine is movicol satchels up to 4 satchels a day. Adding occasionally stimulates and milk of magnesia ect. Now I am struggling a lot worrying all the time and getting no where like sometime adding stimulates a little bit more than I start loose motion for a day I don't take anything for diyirra as it settles on its own but after this my constipation gets so annoying for up 3 to 4 days with so much Discomfort blotting gas some stiffness of stomach.also lot of anxiety and depression. Always thinking what would happen next morn