Panic attack

I just want for a walk to put my baby to sleep and I had one of the biggest panic attacks in my life. I haven't had one in a while and I used to think it was normal. I never knew how bad my anxiety was until tonight. Literally put me in tears. I was terrified by every car and person who walked by. I'm home and and still shaking and trying to breathe. Anyone go through anything like this before? I am finally admitting I have a problem my doctor is sending me to a therapist and I just need some advice.