I had the bleeding every two weeks on continuous progesterone 200 mg, and eventually that turned into bleeding all the time and serious anemia problems.
I did get the mirena coil, and I really didn't want it because progesterone helps me with sleep, but so far it has been going a lot better than I thought it would, it just took some time -- they advised at least 3-4 weeks for it to "settle". The mirena has basically stopped the bleeding after a month, just a little spotting.
I didn't think adenomyosis was diagnosed just from bleeding, but thought it was more related to pain; a couple doctors did tell me I had adenomyosis, more based on pain sx than bleeding, although I had that bleeding problems too. If you have significant pain and not just bleeding, what I eventually found out from a provider was the fluctuations that can happen with estrogen patches can lead to both bleeding and pain with adenomyosis. My doctor switched me to evamist (spray) and I feel better.
Hope something here is helpful. I was worried I was going to need a hysterectomy too, when the bleeding didn't stop, and I'm glad I tried the mirena although I was reluctant. I am curious how things would have been if I had started the evamist with the progesterone and if I wouldn't have needed the switch to mirena.
I do know some doctors in the U.S. think it is okay to do the .1 patch with 100 mg progesterone continuously, especially if you get regular scans. My doctor said it was just hard to know for sure the 100 mg was enough, but for some women it is.