I want you to do me a favor. I don't know exactly how spiritual you are but please do this for me. You can look up on the internet a way to do it. It is called sage smudging. You go to a metaphysical store and buy either a sage stick or loose. Mine was only 6 dollars. You say a prayer of protection, ask for the white light to surround you, and then you light the sage and try your best to get it to smolder. Sometimes you have to light it a few times. You start with your feet asking for all negative energies to be removed by the power of God. Then you go around each door, to the corner of each room, then turn in a circle in the center, continuously asking for all negative energy and entities to be removed. When you are done, put the sage out, say a prayer of thanks, open the house so the smoke and negative energies can leave. You will probably be tired afterwards. Also burining sage smells a little like pot so you will probably want to burn some candles afterward. Sit and relax for a while. Don't forget to open cabinets and closets and drawers. It will help.
My house is so much lighter. When MIL left last year, it was like a cloud was lifted but with everything going on, MLC, my depression, there was still a lot of negative here. I don't really know how I missed it to begin with. I have always been very intuned to energies in places. I think because the shift was so great at first that I just assumed that was all of it. It will also help with the cancer. I know it sounds really stupid to some people, but a friend of mine does her house after our friend who is going through chemo leaves.
If you focus on the past, you ruin the future. You can only live for today.