Major Anxiety and I need help

So my ex dumped me almost three weeks ago and we didn't talk for about two weeks. He wrote me off like I was the one who broke his heart because he blocked me on social media. I honestly thought he blocked my number, though i never tried to contact him because i never had a true reason. I then get a text from him asking for one of his belongings back. Which I mean I wouldn't want to keep it cause it literally has his name on it. He says he needs it before Tuesday but I've been out of town till today. I haven't reached out to him. I do miss him and still have feelings for him. There's also so many things I have to say to/ask him for answers and better closure but I'm having major anxiety, shaking uncontrollably and feeling sick, knowing I have to see him to give him his stuff back and actual talk to him. My question is, what should I do?