Sometimes life gets in the way, and you need to be able to accommodate that without everything falling apart.
If something comes up and you really can’t stick to your plan, then just shift things around. Sometimes life gets in the way, and you need to be able to accommodate that without everything falling apart. If you do have to miss one of your sessions, try to fit it in somewhere else. And if you can’t do that, just carry on as soon as you can.