Struggles with letting go

I'm not even sure what I'm about to write here. I just feel the need to write and think out loud. This is such an exciting time of our lives, with two kids about to take off on their own. The hard part for me is knowing when to help and give advice and when to keep silent. Maybe it was easier for me to not bug them when they were across the country, but I wouldn't trade this year for anything. I LOVE having them all home for one more year. I pray for wisdom in this area all the time. I seem to be making mistakes almost daily. Sometimes hourly. I hate it when I hurt them by my words, but the more I try to stop it seems I just fail more. I pray that God will turn my mistakes around for the good and that our kids will see that I didn't mean harm but only to protect them in these huge decisions. I realize there's a fine line of being helpful vs. over bearing. Maybe I want to be a perfect mom too badly and in the struggle, I mess up more. Here's a verse I've claimed many times through my life. In college I relied heavily on this and took it as a life verse.
2 Corinthians 12:9
But he said to me, "My grace is sufficient for you, for my power is made perfect in weakness." Therefore I will boast all the more gladly about my weaknesses, so that Christ's power may rest on me.