I had the same thing happen to me. I had a huge panic attack once while stoned and for a month or so after I was in a constant dream like state. Massive anxiety as well (I remember I couldn't get an erection it was that bad ). I did think I was going insane which didn't help at all. Plus, I have OCD which made me obsess over the thought of going crazy. (weed helps with OCD btw) What did help me the most was meditation and yoga. It helps you take control of your mind and your reality. You might not be into the spiritual side, but it is the best thing for anxiety. It's totally gone now after a year and I honestly have meditation and yoga to thank. Another thing that might help is (if you're in college) is to take a semester off. Clear your head. It never hurts to take some time off to get things in order. Don't worry, you'll be back in no time Hell, maybe you'll even give weed a chance again