Glucose test, Any tips?

I’m 24 weeks i went for my first glucose test (FTM) few days ago i was told to be fasting for 8 hours+

The process was to have the glucose drink then wait for 1 hour to get blood test, and then wait another 1 hour for the second blood test,

It wasn’t that difficult drinking it but then after i was done she told me to wait outside in the waiting room, as soon as i sat on the chair 10mins from drinking it, i felt so dizzy everything was spinning sat on the floor “ to avoid falling” and fainted for like 2 seconds then i threw up the whole drink and felt better, the test was canceled they told me to get checked with my doctor but she’s on vacation so i got checked by other doctor the next day she told me everything is fine baby is fine and to do the test again on 24th,

Any tips so none of that happen again and finish this test peacefully? 💔