End of life

My mom has terminal cancer. It has been a scary whirlwind. Last year she was diagnosed with oral cancer after being told what was wrong with her was gingevitis. She had a small surgery afterwards that the doctor said to watch it grow. I didn't accept that so she was taken to another cancer place where in September they rushed her in to get surgery again removing a 4 cm tumor from her mouth and her lymph nodes. Everything came back good margins and clear lymph nodes so she was declared cancer free. 6 months later the doctor said no need to do a pet scan so 8 months later she found a swollen lymph node in the opposite side of her neck. The doctor dismissed it saying it was a cold, but she went to another place and low and beyond they did a pet scan and it was definitely cancer. They removed the lymph nodes again only this time the lymph node had burst so radiation and chemo was needed. She finished with flying colors and like a true champ. Two weeks later she found a lymph in the front of her throat. Doctor (same one who messed up before) said it was scar tissue from his surgery. At 3 months after surgery when the PT told her to really get it checked out, she was greatly concerned, they did a pet scan early. Sure enogh cancer, only that was only the beginning, it had spread to her liver, right leg and neck as well as some other various parts including her lungs. She was told chemo for life with a lifespan of about a year or so perhaps longer if she chose immunotherapy clinical trial and it worked. They sent us home. 3 weeks later we went to the doctor she as so tired. She noticed more lumps and wanted to know if she coudl chose chemo instead of waiting for immunotherapy. Her normal doctor was out of hte country so she went to another hospital. They gave her a life sentence of maybe 2 or 3 weeks stating chemo would only kill her faster. She came home only to have her leg break causing a fall. The doctors hoped to repair it but ther was no way as tumors were all over the leg making it impossible to prevent breakage only by replacing it with metal rods but that couldn't be done because her spine is riddled with them. A lung xray showed tons of tumors there too. So they sent her home with hospice care coming. She was sent home Friday and hadnt' eaten since Tuesday when she fell because Boost was not offered in the hospital. She couldn't eat or drink. She still has not eatened or drank only a tiny bit of water is being placed in her mouth to keep it from being dry and uncomfortable. She came home with a patch on and receiving oxycodone by mouth when needed. Pain was managed and she was quite happy. Her grandchildren were visiting as well as her other daughter and while tired, she was quite content. She was talkative, watching movies with us, toasting the new years with eggnog (although she choked on it she tried) Two days (friday to Sunday) after that, she startd having hard time breathing. She was wheezing, coughing, gasping for air so hospice changed her over ot morphene. Now she mumbles unable to talk. She doesn't open her mouth and has very little strength left. She withers around in the bed very uncomfortable and in pain. It fixed her breathing but her pain is now not managed. I have been hitting her pump hoping to help knowing shes dying so i can't possibly do more harm since the hting is maxed out at 2 ml and the lady on the phone from her hospice said noraml starting dose was 2 ml with the pumping by hand making it closer to 3 or even 4. I gave her lorzapam to help her sleep. This is only been 4 days since we were given a 3 week time frame. Is anyone else going through this? Has anyone else? Is this normal to go this fast? How do you know which drug to use hwen the patient can't even tell me? I'm searching for support and perhaps just to be told I'm doing a good job and that this is normal and it will be ok. Why is caregiving for cancer patients so hard and not so straight forward? I assumed I'd have months to learn this stuff and instead mere days.