Struggling with grief after losing my mom

Hello everyone, new to this forum but its to the point where I needed to talk to others. I'm 22 have a fiance and a beautiful baby boy I have a great job but my problem lies in my past, you see I lost my caring mother she was 51 and had a massive heart attack unexpected in her sleep since then the family has fallen apart I feel myself putting up a shield with my feelings my family doesn't talk to each other anymore she was the glue holding us tougher. Since my son has been born the family doesn't seem to really reach out and talk or FaceTime to see him I have my finances family and thats all but I find myself still with a missing void that my mom missed out on so much I would really appreciate anyone's input I just feel like I never grieved properly and its all my fault I fall back into my old ways when I didn't have anyone