not able to feel like she used to, often moody & lethargic

My partner & I have been together 3 years & we used to have a great sex life. We both love each other & want the best for each other. My partner has seen a couple of G.P's with the problem of low labido before but haven't had success with different pills. We were great up until she went onto the pill here in Australia. We know it was one that started with M? Minulet maybe. As soon as she went on that, she changed. Since then she's tried Yasmin & one other. No pills for last 12 months. She hasn't been able to feel like she used to which is upsetting both of us. She's only horny mid way through her period. The rest of the month she has no interest in me, so we have sex once/month. She knows what she used to feel like & wants that back. She's very attractive, so it's driving me crazy! Haha. She's more 'flat' than she used to be as well & often moody & lethargic. She gets violently ill on high estrogen pills. I wonder if she's allergic to her own estrogen or might need hormone treatment?