I once lost 9 people in just under two years. Five of them to lunatics with guns. One who died instantly at his turntables when, while bopping his head to the music in his headphones, his undiagnosed spinal meningitis kicked in and basically turned him off. They say he was dead before he hit the ground.
There's no answer. There's no easy solution. There's no rhyme or reason to when or where you will go to pieces.
It just happens, and breaking down is not a weakness in character or a problem you can "solve".
What I found most helpful was to going and doing things that I know they specifically would have liked. Being active, doing something I may not have done by myself before, or simply thinking "If Drew was here, he'd seriously dig this!" helped me make new, positive memories, of the person and established a new positive narrative that I associated with them, rather than just their death.
Good luck with your journey, my friend.