Hi there don’t stress!
I started the big 3 4 months ago. I took them all in the morning. They started me on Azithromycin rifampicin and ethambutol but only 4 x ethambutol and 1 Azithromycin for first week then introduced rifampicin next week. I haven’t heard of and have not been told of a side effect of passing out. You had the ecg which was fine I’m pretty sure if you felt anything different with your heart you wouldn’t be driving anyway you would be reporting this to a doctor. I had to come off the ethambutol because of side effects tingling and burning in feet peripheral neuropathy. So am on Clofazimine. Taking these drugs is scary but there a lots of people who have no effects and breeze through. Keep an open mind, you could cope well. Some take their doses at night and seem to cope better some take 2 in the am and then the other at night. I take mine early morning Az and rifampicin together on empty stomach with a full glass of water and then clofazimine 1.5 hours later with food or milk. I do get an upset stomach for most of the morning but by afternoon is much better. Be strong, you can do this, you got this!