How to handle depression after a loss?

I have Major Depressive Disorder and General Anxiety Disorder. At 16 weeks on 8/10/19, I lost my daughter and now it either sunk me into a deeper depression or it's PPD on top of my MDD, which my OB was worried about happening when I was pregnant. I can't really tell to be honest. Is there a way to discern the two? I have an appointment with a therapist next Friday but it just seems difficult to decipher the difference between the two of them. The big things I noticed recently were a sudden onset of panic attacks, getting a lot less deep REM sleep and waking up multiple times a night ( I have a watch that monitors it). I could get 8 hours of sleep and only get 1 1/2 hours of actual REM. No wonder I'm so tired all the time. I was recently diagnosed with PTSD too bc of the traumatic loss.