I think your pregnancy and your horomones are playing a very large part in your feelings of anxiety. You didn't say if this was your first pregnancy, but if it is, I thinks it's really "normal" to have some fears about being alone. I know I did during my first pregnancy when my husband would leave. I became quite afraid that something would happen when I was alone and spent most of the day being anxious.
Are you a military wife? If so, that might be a contributing factor. If you are in a new location and haven't made any friends yet, that just adds to your feeling of isolation.
But the best advice I can give you is to find the time to get in to see your OB/GYN and discuss all of this with him/her. Keeping all of these fears and worries to yourself is not helping...........time to reach out, which you have done by writing to us, but we are not doctors and I really believe that is who you need to be talking to right now.
Please feel free to keep posting to us...........there are many new moms here and perhaps they can relate and address your fears, but please make the appointment with your doc!
Let us know how you're doing, OK?
Peace
Greenlydia