Divorce - What am I looking to lose under English Law

I am currently undergoing a stressful time. My wife is looking to file for a divorce due to our differences after 20 years of marriage. I have been the only breadwinner for all our marriage and we have 3 children. Eldest 17 youngest 9. I have 4 properties, 2 jointly owned and one solely. I also have a very successful business with good income. My question is what am I looking to lose financially and in terms of the children. She has already made it clear to a mutual friend she is coming after everything I own so abit worried will I end up with bare minimum. I am looking to gift one of the houses away to a friend what implications will that have? Also will the children still be in my care as she hasn't worked a day in her life. Thank you for the help.