Rethinking everything since 2018

I (26M) have been with my GF (24F) for 6 years on the first of February. Yesterday she comes downstairs crying and I asked her what was wrong. She told me her friend called, saying her grandfather fell, ended up in the hospital, and passed away a few days later due to complications. I obviously sent my condolences to her friend, but I couldn't believe what I was witnessing. For context, my grandfather passed away in July of 2020, and my grandmother passed away in January of 2022. I was raised by my grandparents because my mom was single and working to provide for us, and dad wasn't around, so I spent a lot of time with them. When they passed, my grandfather especially, it hit me so hard that I havent really been the same since. I lost my outlets for my emotions, my best friends, "all that I have" in a sense because they were the only people I felt i could truly be 100% honest with. My girlfriend basically gave me a hard time over being depressed and stressed out over funeral planning and distribution of belongings since I was appointed power of attorney. I have dreams about them that really fog up my perspective in the morning and have to come back to reality a little bit. One morning I woke up crying from one of those dreams and I was told "you have to get over it at some point. You can't be depressed and miserable all the time", but her friend that she only knows maybe 2 years (work friend) gets all the sympathy and support? I have to take it on the chin and be a lobotomite because I'm a man? I'm just dumbfounded and feel like I'm making the wrong decision and have been doing so since we got together. I feel stupid for not realizing sooner but I feel like I don't know what to do. I don't want to be like my father and abandon her. We don't have kids, we do have a dog, but there's nothing other than my guilt holding me and I just don't even know what to do anymore. Any time I bring up how I feel about something I have to change it, and however she's feeling I just have to deal with it cause that's how she is I guess. I'm sorry for the rant but I feel like I have nowhere else to turn