Welcome to PC!!
I currently live on my own and have done so off and on since 2005. It's not always easy to recognize your symptoms at first. I'm only now starting to understand what is going on in the past couple of years. Sometimes other people see the changes before I do, so now I tell close friends and family members to let me know if they see or hear something out of the ordinary with me (my dad lives in California and recognized I was a little hyper in our conversations, which I found out after the fact). Recently I did download a mood tracker app. I don't think it's that great, but the good thing is that it helps me to reflect on how my moods may be changing because I have to think about what was going on that day (e.g. anxious irritable, etc.).
I think working with a therapist is also beneficial, so keep that momentum. If you every have any "living alone" questions, please feel free to pm me.