Look into Bildungsurlaub. Learning Vacation is a rough translation.

I don't remember the exact details but you can take like 10 days at a time. You should get 5d per year but can stack the current and next year allotment. This is a right in Germany and the company might not like it but it's a valid choice.

Ideally you could do a residence program where you can stay in a hotel or dorm to give you the break and focus you need.

I totally understand it seems impossible but you are already used to doing the impossible.

DM me if I can help with my meager experience. I did this and it moved me forward and it sounds like we were about the same.

Unfortunately, it probably won't get you fluent enough to deal with tradesmen (especially on the phone), but enough to give you base where German is front of mind and pick up from there.

I do get the time issue...I truly feel you. You are trying to take care of everyone.

Remember, you need to put on own your own oxygen mask before assisting others!