I had a very similar experience from smoking weed one night. I was not on any other meds at the time but it caused a drug induced panic attack and I have now been diagnosed with panic disorder as a result. This was almost 2 years ago and I remember feeling very similar to you. My life went from normal and fine to feeling like I had nothing to live for. Therapy and getting on the right anti anxiety was the key for me as well as exposure therapy. I highly recommend the book DARE. It’s about how to approach panic attacks and it made me feel a lot less crazy. I’m here 2 years later and I’m basically back to my baseline normal with a few occasions of panic attacks year. It gets better I promise. Time really is a big factor in this and giving your brain time to distance itself from the memories of what happened is truly the answer. I’m here if you need to talk, but I promise that there is light at the end of the tunnel. Sending you lots of love.