Obsessive Thinking and Caregiving

My husband has FTD and is 70 years old. I am a full-time caretaker for him. Today and yesterday he became completely focused on the fact that the ROKU was not working on our t.v. I am not technologically savvy but I have installed several ROKU devices without a problem. This time I could not get the thing to connect to our wireless internet. I worked for a long time. I read advice on the internet. Unplugged, plugged back in, gave the thing hateful looks and finally decided that I would use the t.v. I bought recently that has HDMI. I lugged it out into the living room. It is big and, while not new, much newer than the huge t.v. we have been using. I plugged in the hdmi cables, hooked up the ROKU and VOILA, the ROKU works. Did he say thank you or great job? No! He found a show, said he hoped it was in English and when it wasn't wanted to know if I could make the subtitles larger. I was an inch away from reaching for the cast iron frying pan and introducing him to the "other" caregiver. LOL Once he gets a thing or idea on his mind he cannot let it go until he is satisfied. At times it is funny and at other times it is infuriating. He does not notice nor care how I am impacted by it. He just wants his need met. I have, a few times, stood my ground and refused to continue trying to put a square peg into a round hole, but much like whack-a-mole,. what is suppressed today pops up tomorrow. If I did not have a sense of humor you would be reading about me in the paper.