[Philomath]

Hi Sunflower,

I agree with Holly. You could have separation anxiety however this could be rooted in some other condition such as depression or General Anxiety.
I know that before going to college when I was given time alone at home, I always got anxious. I never worried so much about the safety of those that were not around however I worried more about the fact I was alone and had no one with me.
It could help you to have short periods of being by yourself that extend to longer periods (this can be done by those that live with you).
In relation to your girlfriend, it is understandable you would worry about her safety (particularly if she came from an abusive home environment) however if you know she is out of that environment, try reminding yourself she is safe and if she has not given you any indication that there are problems with your relationship use the security of it as a comfort in some way when you get anxious about things.
It could help for you to talk to a mental health professional to figure out more appropriate ways to get over this anxiety in a manner that is comfortable for you and will help you best with overcoming this aspect of your anxiety.
I hope this helps and that you can get help for this.
Take care.