I had posted on 8-9-20 about my mother passing on hospice on the 7th and the guilt I was feeling. I've been working through that guilt and grief as best you can. My MIL passed, on hospice, from cancer on 9-11-21. Also, my only brother was killed in a motorcycle accident on 10-3-21. To say I'm having trouble with grief and depression right now would be an understatement. I love my wife and children and I wouldn't harm myself but that doesn't change the fact that I feel like I want to go with him.... what doesn't kill us makes us stronger..... right?
Adding to the loss of your mom is the loss of your brother.
Have you given any thought to talking to someone about the grief that you are dealing with. And I would imagine you are feeling "guilty" as well.
You have nothing to feel guilty about or for.
Hospice does have Breavement Support Groups as do many places of Worship, Senior Centers. I think you owe it to yourself to seek out a group or if you are not a "group person" private sessions might help.
The old adage you use..."what doesn't kill us makes us stronger" .. may be true but often what might have killed us makes us weaker and we must work at getting stronger. That goes for the mind as well as the body.
I think a visit to a doctor about a antidepressant may be in order, along with some talk therapy.
It is perfectly OK to feel what you feel--in fact, you HAVE to feel what you feel and not shove down the emotions that come at you. That will only lengthen the grieving process.
I personally dislike that 'what doesn't kill you makes you stronger' thought. What doesn't kill us often takes us to our knees in grief and sorrow and we do not have the skillset to 'fix' ourselves.
I wish you peace and hope going forward. Reach out to those you love with courage and honesty. You may be pleasantly surprised at the support you receive.