Separation anxiety

I am experiencing depression and anxiety over my 18 year old daughter going to college. I was upset her first year when she went off to college but this is her second and I cant stop thinking and worrying about her emotional and physical well-being.

I am very upset when we speak and she is under so much stress from school. I also am very worried about her personal relationships with friends and boyfriends. I feel I am becoming obsessed with these thoughts. Do you have any suggestions?