I realize you're looking for a reason to understand the life events you've experienced, and that you feel the number 18 is a key to that understanding.

Numerology can't be used to reliably predict a time of death, nor can it do so by knowing the timing of deaths already past.

Some may come up with certain calculations and say they could have been used to predict a death that's already happened. But nobody making those declarations has ever been able to predict with accuracy a death in the future. Reliable death prediction calculations and declarations can be made only after the event has occurred.

The number 18 may be a key, although I wouldn't know which lock it fits. The number may also be coincidental. With four different dates, it may be (I haven't calculated the odds) more unusual for them all to have different numbers than for one or more to be repeated several times.

The number 18 is an interesting number in its own right. Click the link for the information.

Further, the number 18 is reduced to the number 9 for determining its basic essence.

Your name number is also reduced to the number 9. Thus, your name and the number 18 resonate well together.