Hi LisaRose,
Welcome to the forum (as I have not welcomed you yet).
I understand all too well what you mean by feeling alone, even if you live with people. That seems to be a trademark of PTSD, I am sorry to say. I also understand your frustration when you say you want your life back and all that doctors seem to offer is one medication after another. PTSD is a long-term deal and can affect every area of your life.
As for ideas on how to get through the day. I am not sure I am the best person to suggest things as I tend to struggle with that, too. For me when I am struggling the most my day revolves around my dog. I love him and he is my best friend. I feed him when he tells me it is breakfast and dinner time. Before bed time we have our bedtime snack of ice cream. Doggie ice cream for him and real ice cream for me.
Otherwise I spend most of my time in bed on the computer. I watch television series and movies online, documentaries when I am curious about something. I read a lot of information online about people's lives (real people with problems or medical diagnoses I can relate to). I also enjoy looking up new topics and learning about them. I usually force myself to leave the house at least once a day to run an errand or at least to go on a walk with my dog. Our errands are to one of our safe places (e.g. library, Y, grocery store, book store, therapy, doctor appt).
When my concentration is good enough, I try to work on my dissertation and other university tasks. I ran some errands at the U on Monday with the help of my ILS worker. I have all my requirements completed other than the dissertation and the defense. Luckily, there is no hurry on finishing those as I am officially on medical leave. Sometimes I dream of the future, when I am finished with my Ph.D. and look for options for then. It will take a few more years of significant therapy work to get there, but it is my version of window shopping.
If I am particularly antsy and need to move my hands, I either work in the yard or ask my neighbor if I can help her with her flowers. I have also found some activities that help with that antsiness (e.g. making tie fleece blankets, puzzles, painting, playing with clay).
I hope this helps...