Yes, you're right that '100 years on Earth seems like a couple of minutes to our loved ones in Heaven'. That is what I too perceived in prayer and meditation. Also, it is comforting to know that, even though we cannot always see our loved ones who've crossed over, they can see us. Just thinking about them connects us to them. I know how painful it is when a parent dies so I wish you peace and comfort during this time.
The LORD is close to the brokenhearted and saves those who are crushed in spirit. -Psalm 34;18