Somebody PLEASE help me with my sleeping problems! Thanks?

Ok, so I'm absolutelyt fine in my own bed it completely ruins my holiday as i can't sleep in a bed that is not my own! No matter how comfy it is. I know that it's all phycological and I can never sleep when I'm worried, so when I lie down in bed my heart beats so fast because I am so worried about not being able to sleep. Once on holiday I fainted from exhaustion! I know I just need to relax but I just can't calm down. I end up not sleeping until 4:00 am or even not at al....PLEASE any suggestions?!!