I am a divorced mother of 3 grown children. My exhusband is very wealthy and has bullied me and turned my children against me. I have tried everything to make them like me and I can't win! I'm tired and hurt; should I give up?

Not give up, just be yourself, live your life, and wait to see if the children decide to return to relationship later

You are probably trying too hard. Stand back and let human nature take its course.

You mention his wealth as though it explains everything. He uses money to get them on his side against you?
If so, try to realize that only works for a while in most cases. Even grown children mature as they grow older.
Plus, if you dwell on that, you are merely accentuating your bitterness, and possibly even making excuses for their preferences.
If you can try your best to be worth loving on your own merits, they will love you.
I realize that is easy for me to say! It's just a goal to try to work towards, a certain acceptance of how things are - he's rich and you aren't, c'est la vie.

Build a life that you enjoy without husband and kid just encase the ungrateful bast@rds don't come to their sense for a while.

Why should you be unhappy because they are stupid? Yeah its sad but what' a person to do? How old are these kid?

No, just get your own life going and stop spinning your wheels. Take a course or two at the local community college. Travel, even if it's discovering wildlife or historic homes or woodland trails in your own county (but if you go to Umbria, Italy, please take me with!). Join a book discussion group or writers group -- or start one. Your local library will help you find one or start one. Volunteer at a nursing home or animal shelter or hospital and get back in full measure the love that you give. I envy you with all the opportunities in front of you. Been there, done that, and could keep you up all night with exciting or funny stories. Now it's your turn!