Please explain it to me

So my father passed earlier this year in June. He was my best friend and we were very close. He raised me and my brother by himself. He loved my two boys with all his heart.... Fast forward to now. I have dreams with him almost every night. I will yell his name and try to get him to look at me or talk to me but nothing. It’s like I am not there. Then when I get close enough to him or something he is gone. What is going on? Is he lost? What does it mean? Please