Hi Aw511,
I was just dx'ed with dependent personality disorder as well. I went to get tested for ADD... .ended up being told I have DPD, ADD and PTSD. I am sad and feel a little hopeless. It does help to understand why I get into/stay in unhealthy relationships but I am scared I will never have a normal relationship.
You feel totally broken - but you are not! The fact that you are reaching out for help is a sign you are a lot less broken than you momentarily feel. You see something is broken and take action to find out more is very healthy. It can be also painful . Feeling overwhelmed with anxiety in such a situation is normal and ok. Anxiety is the hallmark of PTSD. It is almost expected to feel overwhelmed when struggling with PTSD.
Don't forget that just because you currently suffer from many symptoms does not necessarily mean all is broken or it is very hard to fix. Most people on this site have or have had significant attachment issues. Even if they were semi healthy before their relationship their instincts are confused after it. A lot heal by themselves, some need outside help. In any case it takes a while for the situation to normalize.
I thought I had worked through so many problems, and now this... .It's never ending. I just want to be happy
The fact that you overcame so many adversities is commendable

. Some may have been truly overwhelming When situations were overwhelming and you were still able to cope that is great

It does not mean you have sufficiently processed or safely discarded the memories of these situations. And when some of these possibly even unreachable memories raise their heads and cause their own dysfunction it is time to take action. Good to see that you do You may find this book useful to navigate your options:
https://bpdfamily.com/message_board/index.php?topic=213669.0