I Think I'm A Medium

The other day, I was at work and a little girl around age 6 appeared to me, I see her plain as day. She just looked at me and said Elizabeth. She is always around me and talking to me. She's told me she wants daddy amongst other things. Later that night, an older man tall and skinny, late 90s and short older lady in her 80s came through with this Elizabeth. I had feelings of my chest hurting and cancer of some sort. I've asked my husband and neighbors and apparently this Elizabeth is the neighbors little girl that died shortly after birth and the older couple is his great grandparents who he hadn't told me anything about. He told me his great grandmother died of a heart attack and 6 months later his great grandfather died of broken heart and cancer. I shouldn't know these things without him telling them to me. A older lady by the name Paula has been showing herself which I have found out is the neighbors grandma whose pasted. I'm a little freaked out. If I ignore these spirits I get a really bad headache. When they come through I go into like a trance and constantly tap my fingers. I get names of people a lot and images. I've also experienced a vision of and man in his 30s walking across the road and a red vehicle. He was hit which I felt and he was badly hurt or killed. His name was Derek but no one I know has a Derek that is decreased. The only time I get quite is when I'm asleep. I've heard my 10 month old daughter talk to me in a voice as plain as an adult talking. I'm a little freaked out by all this. Can anybody explain this?