I'm going to tell my wife that I'm no longer comfortable with the fact that she vacations with her ex-husband and kids without me and I think it's time to make some changes
What makes you feel uncomfortable about your wife vacationing with her kids and her ex-husband?
I am afraid that she wants a divorce. She already never has sex with me anymore and I don't want her to do everything without me.
It's understandable to feel left out when a partner goes on vacation with someone else. Additionally, it is concerning that your spouse no longer wants to have sex with you. You should talk with a couple's counselor to try to work out the issues in your marriage and also try to repair your relationship or otherwise it seems that divorce is likely.
I'm so tired of this.
It makes sense that you're tired of this, because it sounds like a tough situation. I really think you should talk to your wife, and maybe get counselling together, because this doesn't seem like something that you'll be able to figure out alone.