Hi I get really distressed when people leave me and I really don't like being alone help me?

How severe is this? Do you mean the departure of partners or friends or people at home?
If you find it very difficult to be alone at all, it would indicate some kind of acute separation anxiety or a problem with dependence, or perhaps even a very weak sense of identity. In any case, it's a crippling thing, and I'd look for professional help.