I also suffer from severe depression and anxiety, and I have found help through medication and counseling, but I still have that feeling of not being able to breathe when I am going to sleep. This still happens to me, especially during times of stress. I've had many nights up until 3 or 4 AM for this reason. Even taking my med doesn't calm the symptom down sometimes, but deep breathing helps me some. I hope you are seeing a doctor about your symptoms, and hopefully you will get some help. The racing thoughts is a real sign of anxiety.... I have that, too. Glad you're here and hope you stay ((((hugs)))).
"It's a jungle out there....."
Theme song from "Monk" by Randy Newman
"Turn this car around... I'm goin' back..."