Hello I Have Been Abusing Ambien For Over A Year

Hello I have been abusing Ambien for over a year now and I noticed that I have taking twice my prescribed dose. I stopped for 1 month cold turkey and had several panic attacks and had issues sleeping the first week then symptoms got better. After that month without use I started taking them in smaller doses of about 5MG but now I when i take them I get anxiety and the next day I’m having shortness of breath until
I take them again at night and everything is good! Why only when I take them am I ok?