How do you effectively reduce the dose of tridestra without having to many symptoms

I have been taking Tridestra since 1999 which was prescribed by my GP after going through an early full menopause - I am now 54 years of age and have never experienced any problems whilst taking Tridestra. However, after finishing my last 3 monthly course and when taking the yellow tablets instead of having just slight bleeding I have had all the systems of a normal period eg. heavy bleeding for a much longer period (full week) sore breasts, low back pain, low abdominal pain. Could you advise if this is common or do you think that because I have been taking Tridestra for such a long time may be it needs changing and I need to consult my GP?

I have had the same as above the bleeding at the moment is so heavy i have used 40 tampons in 12 hours?