Hello,
first of all: Thank you so much for the many answers. I will provide a log and further details on my training, body etc. in a next step.
The bloodwork came in and everything (except Magnesium) looks fine. It was interesting to notice, that potassium is in the upper normal range and that I definitely should stop supplementing that. However, it seems that the Salbutamol massively dropped Magnesium level. This is very interesting, because I did not read anywhere, that it could have such an effect on Magnesium.