You could ask to try separate transdermal estrogen and utrogestan (body identical progesterone). You could still have a patch, only it would just have the estrogen in it - and then the progesterone would be body identical, which is better for your health anyway - instead of a synthetic progestin, as in Evorel Sequi.
Many women find that body identical progesterone (utrogestan) is less likely to cause low mood than synthetic progestins.
Plus, if the utrogestan doesn't stop the bleeding orally, you could also try it vaginally. It tends to have a stronger effect that way, especially if you use the same amount, so it might work better for you.
Otherwise, yes, the Mirena coil and then separate estrogen. I don't get what you mean about your age... If you take HRT estrogen at all, you need something to keep your uterine lining thin - that need isn't going to go away no matter what your age is. You will still need a progestin at age 80 if you have a uterus - and if you don't have a Mirena, it will be another form of progestin. Women can continue to get Mirenas fitted for as long as it is comfortable to get them fitted and removed - way into their 60s and beyond, often. It will probably not be your one and last Mirena if you get one now... And you don't have to leave it there for 5 years either - it's your body and if you ask for it to be removed, it will be.