Im lowk struggling in life rn

Im 19f and I’m experiencing something that i feel no 19 yo should go through I had a twin sister and recently she passed way from suicide. Idk what to do with myself anymore It feels like a part of me is missing. I have alot of people saying I understand what you’re going through but unless you have a twin and they have passed way you really don’t know how it feels you know. It’s such a different feeling I’m here mainly asking for advice on ways to grieve. Note. I’m active duty military and my twin was active duty as well.