Someone on a FB group that I'm member of recently started a thread about problems with family. So many people responded to that thread from a very small geographical area that I'm beginning to think family problems are as normal as not having problems. There was a lot of psychologising on the thread about "narcissistic" siblings, parents etc - seems to be the new word on the block.
If you have sons who are talking to you.... at all..... I would say that means that you have all done something positive relationally!
TishaBuv, you write often about family letting you down - your siblings and husband and kids. Jeez, I am the last person to comment on that since I've had no immediate family to speak off since a very young age and I am a complete doofus at intimate relationships. It would be lovely for you to have a warm, happy family - both family of origin and current family - but already you have a lot

!!! You sound like a restless person wanting to find a new way to use your energies.
For me, telling others that I'm disappointed in them is sometimes about decreasing the loading and intensity of my feelings beforehand so that they can hear me better.
Perhaps with adult children, it can also be a question of consciously building a new relationship with less expectation on either side?
However, my big relief in not having children is not having to deal with my feelings about my in-laws!!! Best of luck with that one!