You can post here and talk in chat if there are people there who are able to listen. I find here easier, but that is probably personal.

There were some striking similarities between the experiences you describe and my own. Like you, I was really close to my Grandma. She died in 1994 and like you I really miss her. The pain of missing her has resurfaced for me recently. I am trying to remember her as well as missing her - remembering how she loved me and how she made me feel loved. She did all she could to make me feel safe, and I know she would be sad if all I focused on was how much I miss her. MAybe that could help you too? It still hurts that she is not there, but I can remember what she tried to give me was the courage and confidence to live my life.

I have similar things with my kids - I really want the best for them. My dr yesterday gave me some really good advice which I am trying to follow, He told me that, instead of focusing on the way I did not meet my parents' expectations, I should try to recognise how much I am doing to make my children's lives better. It is hard to do but has really encouraged me.
Trust is a hard thing too. Online can be a good place to start trying out trusting people, and you are doing a brave first step by posting here what you have.
I'd add my voice to the others who have suggested trying to find a therapist or counsellor. It can really help. Can you talk to your dr? He/she should know how you are feeling too.
There is a lot that you can do and others can do to help you. You don't have to feel like you do now for ever. Keep on posting here - I hope you can find some support in 3D too.

Caroline