Hi Linda,
You're not alone. Though we -- all of us here -- may be separated by great distance, the internet has made it possible for us to be together for support.
There are a couple things "they" don't tell you (maybe because "they're" hoping they won't -- or don't -- always happen(?) I dunno.

).
First, Depression is part of the package. It comes with any kind of chronic illness, and the two feed on each other in what has been well-documented as the "vicious cycle". Google:
chronic illness depression vicious cycle
Second, the stages of grief. Chronic illness is a life-changing event that affects not only our bodies but our minds. Google:
stages of grief chronic illness
Knowing about these things won't make them go away. Learning about them will help you recognize what you're feeling, understand why, and hopefully how to better cope with them. I believe knowledge is power because I have seen and experienced it in/on my own journey. Knowing and recognizing is more than half of the battle in coping, living with it, and moving forward. It is not the end; there is still great joy and wonder ahead.
Venting is fine and healthy. Anger, frustration, depression... are understandable and forgivable. All of this is human. Forgive yourself first.
Doc