Vomit but nothing comes out

Hi, has anyone experienced vomiting but nothing comes out? I’m on week 12 day 6 and have never experienced this before when I was in first trimester but it has already happened more than 5 times for 2 days. I can barely eat or drink anything. I vomited food out the night before but the next day it was all just saliva but uncontrollable vomit. Does anyone have any advice please?