Hi. I'm not sure I can offer a great deal of help, but I do fully understand how you feel. My mum suffered a brain haemorrhage last year, and whilst having made an amazing recovery from it, has a range of other health issues that are an ongoing concern. As I type, I'm waiting (dreading) a phone call regarding her Mum, my Nana who is terminally ill, and rapidly approaching the end.
My dad lives with two cancers, had major surgery for a third last year, has had a quintuple heart bypass some 6 years ago, and is currently mid way through a series of tests, appointments etc which we believe will diagnose another cancer (one that has rubbish odds). Mum has done a great deal in caring for and supporting him, on top of her own health challenges, and I fear that losing her Mum is going to hit hard (and I think her Dad will follow shortly for various reasons). Mum is 67, Dad will be 86 next month. I'm 37.
I am currently not working - stress and being a single mum to 3 boys left me utterly battered - the only way I can support my family (kids and parents) is by not being a complete wreck. I am looking for a part time role rather than full time - can't afford to not work.
Sorry for the ramble...... do you have a local hospice or service that can provide some additional hands on support in caring for your parents? Without wanting to sound 'cold' either, perhaps it would be appropriate to have a conversation with your parents (difficult though it will be) about what they want in terms of end of life care, where any important documents (mortgage, insurance policies) etc are kept, and when the time comes, how they wish to be remembered and celebrated. Are there any groups local to you who provide support for folks caring for or living with the illnesses that your parents have - sometimes being able to chat with someone who knows what you are facing can help, just to get it off your chest and have someone listen and understand how you feel. And lastly, are you able to take any time off work, or request flexible working maybe? You have a lot going on, and it is hard, it takes a toll - to be able to support your parents as you want to, you need to take care of you too.
I don't know if any of that helps (probably not!) but you're not on your own, feel free to offload, rant, scream or anything else - happy to listen if it helps.