I am so sorry for your loss, and what strength you are showing by sharing this story. It can be so isolating to go through a grief experience that other people don’t understand, and even though the feelings you describe are completely normal, that doesn’t mean other people know how to respond to them. Your instinct to find support groups is a great one, even if the person they lost might be different, many of the challenges people face can be quite similar, and many of the strengths that carry us through are ones we don’t see, at first. Finding a way to focus on our strengths and use them to make our way towards feeling better is a great step to take – this page will help you, if you haven’t found this already: https://griefline.org.au/resources/grief-recovery-part-2-recognise-and-engage-your-strengths/
I’d also encourage you to look through the GriefLine forums and read the stories from others who’ve shared here; all our losses are different, even if their relationship to us is the same, and hearing how others are feeling and coping can really help to not feel quite so isolated.
I hope you post again soon and let us know how you’re going.