How can I honour my schedule?

Every week I apply Monday Hour one and list all the things I want to achieve in the week. I allow time for each task and put it in my daily calendar. Most often I cannot stick to my schedule. I realise that either I put too much in a day or I struggle in evaluating the time allocated for each task. Since we are in lockdown I find it difficult to plan work while answering the needs of my kids (home schooling and being a working mum at home) and ongoing interruption from them. I end up being frustrated for not achieving what I had set to do. How can I approach this differently?