@khajavali123,
I think you've got Buyer's Remorse, and you're tired of the responsibilities of being a husband and a father.
Well, guess what? You married your wife, and you have a child together. Even if your marriage ends, you will still have responsibilities to your child. And your ex is married to someone else. Approaching her and confessing your love or whatever would be unfair and unethical. Besides, you have no guarantee of any sort of a positive outcome. If it were me, if I were the ex you were pining for, I'd kick you to the curb, because you already had your chance.
Instead of spending your time whining about your lot in life, maybe try to improve it. I suspect you're in a country where divorce is extremely rare and unlikely. So you need to make the best of things. Start off by involving yourself more in your child's life. Change diapers, take your child out for walks, read to your child, etc. Even if things are horrible with your wife, you need to do right by your child. Man up and do that.