Have you done a recent FTP-Ramp test, or, are you basing your perspective on the one you did in Feb '18? In any case, sounds like your riding/training had been unstructured of late. I would do another Ramp test and return to SSB I-II or something similar. Don’t worry about heart rate, just do a plan and stick with your FTP-Ramp test result. Your HR will improve (come down) with more structured and consistent training that moves out of your lsd “endurance” zones and into Steady State, Threshold, VO2, intervals, etc.
Good luck.