Really bad anxiety? 😞

So long story short I've had anxiety for around 11 years (I'm 17). This year has went really well for me, school has always been an issue (physically being in the building) but I wasn't having many problems at all. But for the past week I've been so overwhelmed that I've been feeling extremely sick (nauseous) every single day and it's been hard to get to class. I've had two pretty severe migraines over the past two weeks as well, all from the stress. I've barely been sleeping, I toss and turn all night. I feel like I'm starting to lose control again and I'm so scared. I've missed a couple of days of school and now I'm struggling to catch up between AP exams. I've barely been able to do any homework because I've been feeling so ill, and I have no idea what to do. I'm a straight A student and very conscientious but when my anxiety gets like this I have a very hard time dealing. What should I do? Should I go to my guidance counselor and ask for help sorting out makeup work/talking to teachers so that they're a bit more lenient? :(
(By the way I'm seeing a therapist and I've tried meds, they didn't work)