I don't know what to do anymore

Somedays it feels so incredibly difficult. I feel so alone that its painful. I have learned how to journal and write about my anxieties, but dealing with lonliness is something else. I am deeply missing someone I used to date over three years ago. I havent talked to this person since then and I dont know if I ever will be able to. From the day we broke up to today, I feel like nothing has changed. I still feel so awful about it. This grief completely eaten me up inside. I'm a totally different person. What am I supposed to do? I have met so many new people since we dated, but no one has felt the same. Am I just supposed to keep going on being depressed because I wasn't sure it was going to work out? I have a good paying job in an essential industry and I could care less about any of it. I could care less about my future. Nothing I do has meaning without someone to share it with. Meanwhile, I am forced to watch my friends start families and am expected to support them. If I won a million dollars tomorrow I literally could not care less. Why can't I get over this. Drugs and alcohol dont help. They just make me feel worst. I just don't know how I'm supposed to get through this.