Locked into a lesson.
I cannot escape Adverbs. My first lessons were okay but in time, as I became stressed through the number of repeats, they were not as good as my epilepsy was rattled. After several Re-do lessons and no end in sight, I shut down my device. Yet another re-do. I had a seizure, through the stress, took 24 hours off, then switched to the web site and did yet another re-do. Admittedly the quality was failing a little but nothing dreadful. Yet another re-do. God knows how many I have done. All I can think is to buy streak protection each day til I feel able to face this blinking nightmare again. I love Duo, but wow!
Please protect your health first ! I too have epilepsy , though not to your degree. However I do have moments where my body is telling me to back off what I am doing , and I obey. The cost is too high.
Regarding Duo , I too get frustrated on some sections and I just can't get through them. When it gets too frustrating and DL is no longer enjoyable I get myself out of the lesson.
When the learning process starts causing severe frustration ( or worse in your case) I just bail out. I note what I am having trouble with and research it on the Inet. Then I go back to easier lessons and regain my confidence. The next day I try it again. In time the rules/conjugations start sticking and eventually I make it through the stubborn lesson with no frustration. Sometimes it takes many days to get through the lesson , but I always know that I will eventually make it. So will you .
Best to you
To battle Duolingo's repetition, work against the clock. That's my method. As you become familiar with the exercises, the ones you know well become second nature and you can answer quickly. I exclusively work with the timed exercises. I also feel this mimics real situations in which you have to think quickly.