Is Syncope Normal? Is it related to brain damage?

I’m a woman in my late 20’s and I’ve started experiencing ‘blood allergic’ (passed out when I saw blood) at 19 y/o right after I donated blood in a school event. After a few months, I’ve experience it again (passed out) when I visited my cousin in a hospital with a box of blood under his bed (due to pneumonia). This time around it’s a bit different because my parents told me that I had a bit seizures before I passed out. In August 2020, when I had Thalassemia test in a gov clinic where I need to withdraw my blood a bit, I passed out again with slight seizures and this time I unconsciously peed in my pants. The doctors quickly did an ECG test after that and the result turns out to be normal. They said it would be due to syncope. No further check was done after that. But the doctor did advise that if this happened again, I will need to go to emergency department immediately because it might be related to brain damage/problem.

I would like to know whether my condition is normal with having syncope? Or is it true that it’s a sign of a brain damage/problem? What should I do next to ensure I’m all good? - I do experience headaches and/or migraine sometimes. Appreciate your advise/help. Thank you.