What can i do to reduce stress and anxiety?

while going through a horrible divorce ?? my ex husband is constantly making problems for us. he doesnt actually DO anything illegal, he just makes sure he appears when the kids are here, so they cry to see him. then when hes here , he will have a go about my ''bad ''parenting, and the fact that my partner is lebanese he will call me a slut in front of my kids. this always ends up with an argument and the kids in tears , my idea now is just to call the police if he turns up unannounced and doesnt go away. but the stress is taking its toll on me. im fighting with my new partner, losing all interest in everything, and have asked to be put back on anti depressants. any ideas how i can make my life easier without shooting this man ?? thanks