Dretine pill side effects

I've been happy with this pill for 17 years. It regulates my periods, and gives me much less period pain. I have adenomyosis (similar to Endo) and it has kept symptoms at bay. I have never got pregnant on it. The only negative side effect I feel, is that I'd say the top 3% of my happiness is shaved off, but I don't notice it day to day.

I was prescribed Dretine as a 'cheaper' version of Yasmin (the pill that I originally wanted to try) with the aim of regulating my then-heavy and unpredictable periods and clear up hormonal acne on my jaw/chin. Dretine definitely cleared up my skin and started to regulate my period, even though my very first period on it was horrendous (heavy and painful bleeding, although this might have been exacerbated by the fact that I hadn't had a period in several months beforehand). However, I stopped taking it two-and-a-half months after going on it as the nausea was unbearable, especially during the 'ovulation' period - I kept being sick and experienced terrible diarrhea around day 14/15 of my cycle, which was the worst sickness that I have ever experienced. Despite having since switched to Yasmin, my sense of taste is still different (i.e. I find the smell and taste of certain foods and drinks, such as coffee and certain meats, absolutely revolting). I also experienced some headaches, which have mostly disappeared since switching to Yasmin.