Hi,
I'm also learning English and German but on different levels (B2 English; A1 German)
I've stopped learning German recently because I wanted to focus on English and It was a bad decision ( Now I have to remind myself a lot) so I don't recommend this method
For me, the best option is to learn for 30-60 min one language and then the other one for the same time - nothing new
Have you ever tried learning these two languages at the same time? For example, I tried to learn German grammar from English video :)