What do you do when you can't fix the present

You can temporarily accept the unacceptable. Find anything you can in the present moment that is neutral or better than neutral. For example, if you're getting chemotherapy, you probably will feel tired, nauseous, and generally lousy. You can find something with your five senses that feels ok. For example, a nice sunny day outside, a warm, cozy blanket, listen to an interesting audiobook or comforting music. You could be looking forward to the day when you will feel better. It can be work, but finding something positive to focus on, will make you more likely to feel better in the long run.