[header] How to cope when your adult kids alienate you [title] Reflect on the estrangement honestly. [step] It can be easy to look back on your history with your child with rose colored glasses, absolving yourself of guilt, or saying that you're a better parent than most. However, this will not fix the issue nor help you to cope. 
Think honestly about your relationship, about the times you have hurt your child, and the times that they have hurt you. [substeps] Write down your thoughts in a journal.