I got a thermostatic shower mixer from ikea and it's awsome. Just set your preffered temp and it will make sure it stays that way. It wasn't even that expensive. I wish more people knew about it.
Europe is not one homogenous continent. Here in Europe where I am they are not common, and I've been to at least 2 other countries here in Euorpe where these mixers were not common.
I found cheaper options too, but decided to go with ikea because they offer replacement ceramic cartrige which is apparently the only thing that can break on these mixers.
You might want to have the mixing gasket replaced in your shower. It’s responsible for mixing hot and cold water in your shower and can be the culprit of your shower being too hot or too cold. They have a limited lifespan and need to be replaced eventually
I was in a doom metal band call Melty Melty Bones. We had to call it quits because it turned out that our music rumbled at a frequency that caused osteoporosis.