My diagnosis also changed from major depression to bipolar 1. Even hospitalized for a manic episode it still took me a few years to finally accept the bipolar! I also have BPD but never really had a problem accepting that.

The bipolar really threw me for a loop. However my meds are working and my prns work when I realize to take them. And I recognize the differences between the moods and also realize that what I felt was decades of deep depression was probably a lot of mixed episodes along with the depression.

I wish I didn't have bipolar but it is what it is.

I also do have PTSD but it has been untreated and I am old now and feeling newly stable again so I probably will leave the PTSD issues alone. They really aren't bothering me that much at this time in my life.