As someone who's about to walk that same path, the grad school nightmare, I feel your pain. Many of my friends have already went through grad school or are going through it currently and the anxiety is very normal. I expect I will have a total meltdown at some point too. Don't be too hard on yourself, grad school is designed to test your limits not necessarily how academically bright you are. They intentionally stress grad students to make sure we can hack it in the real world. If you have a 3.85 then you are apparently dealing with it better than you realize. Maybe consider getting a bike to ride to de-stress occasionally. Hang in there it will get better I'm told.