I deleted the app on my Iphone. I don't regret at all. My mind seems clearer, not swamped into unnecessary content curated by the algorithms. I loved Instagram because I love painting, and photography, and visual arts in general but these past years it has become terrible with all the videos, and advertisement. And to answer your second question, when I feel mentally exhausted I try to do something physical like going out for a short walk. Seek boredom is an excellent advice !