Some people are progesterone/progestogen intolerant.
The Mirena gradually secretes a lower amount of hormone over time, with the first six months being the highest, when there is an increased likelihood of side effects. Maybe you were OK with it when you were younger because you had higher levels of your own hormones to counterbalance that.
You may tolerate Utrogestan better as it's body identical rather than synthetic, as is the case with Evorel Sequi and the Mirena. You also have the option of trying it vaginally (off license) if you get side effects, which often helps with the sort of side effects you describe, as it is mostly absorbed locally, where it is needed. If not, you may need more specialist help
Such a shame that your GP is so dismissive but sadly, an all too common reaction, probably through ignorance.