Taking care of Mom: Most rewarding and difficult thing I’ve ever done

Good morning,
I have been reading these posts for awhile now but have never posted myself. At the end of June, my 76 year old healthy, vibrant mom was diagnosed with stage 4 lung cancer. It started in her left lung and has metastasized to her right lung, lymph nodes in her chest, right hip, tailbone and brain. Her only symptom was some shortness of breath which was so gradual that we thought it was allergies. I have been taking care of her since the beginning of July, living with my dad and her. My husband and 2 children who are still home, (we have 6 kids) help and visit us daily. All of our lives have been turned upside down. In the beginning, she had 5 radiation treatments to her hip/tailbone and 10 whole brain radiations. She started chemo on her last day of brain radiation. She had at least 14 lesions on the brain and her last scan showed 3-5 are still there. She has now had 4 chemo treatments ( alimta, carboplatin and keytruda). She is so, so weak and tired, absolutely no appetite and cannot do anything herself. About 5 weeks ago she developed a blood clot in her right lung that had broken off from blood clots in her left leg. She could not be on blood thinners because one of the brain lesions had hemorrhaging around it. They inserted an IVC filter that will hopefully stop any other clots from traveling. My mom is my best friend and it is horrific seeing her go through this and watching her decline in front of my eyes. I have two older brothers and they help when they can, but Mom wants me and I want to be with her because I know what is going on best, if that makes sense?? Her oxygen drops significantly on exertion - not sure if it is the blood clot, cancer or both?? Since she was diagnosed, we had our first grandbaby( they live 8 hrs away and we have seen once- (she’s beautiful :)), our oldest daughter got married, our Second daughter moved away to college and I took a year leave of absence from my job as a teacher. So many changes…..I am so blessed to have been able to do this and take care of Mom, but sometimes it gets difficult. I am thankful to have found this caregiving page…taking care of my mom is the most rewarding but most difficult thing I’ve ever done… I don’t want to lose her….