Your teenager blames you for the divorce and will not forgive you.
Divorce is never a pleasant situation, the separating couple, however civilized will still cause upset and emotional fall out around them, no more so than for the children. More and more divorces occur when children are in their teenage years, when adults think they are more capable of handling the situation or financially the parent can manage on their own, going to work and not having to provide child care for their teenagers. Part of divorce is a sense of betrayal on the part of at least one party, and often the children feel that their parents have let them down.
When things go wrong, teenagers look for someone to blame, they do not have the emotional maturity to comprehend that sometimes nobody is to blame. This need to blame someone can often split a family down the middle, sometimes based on gender with sons supporting their fathers and daughters supporting their mothers. It is just as likely to be the other way round, as the son believes they must now be the "man" of the house, a role they are not ready for and they are angry with dad for forcing that upon them, at the same time they are protective of mom.
Teenagers are legally old enough to have a say in which parent they live with after a divorce unless there are risks attached to it of which the court is aware. This can cause tension and arguments as siblings disagree over where to live and more disloyalty is perceived, fuelling the emotional cauldron and causing further divisions. The teenager in this situation has limited control of what is happening, they can choose to live with mum but they cannot make dad come home.
They see mum crying and blame dad, this anger can make them act out in a number of ways. It is made worse if one parent also blames the other and did not want the divorce. The temptation to rail against the absent parent to your teenage child, who is a semi-adult, is very strong.
Parents have made the decision, and even if one does not agree to it, they must realize that they are punishing their child further by bad mouthing the absent parent. In a small community the divorce will be the topic of much discussion and your teenagers will be upset by this; they may get into fights, start drinking or hanging around with other older young adults to get away from the feeling of helplessness the divorce has created. Do not make your teenager pay for your adult mistakes. Get some help for them, and you, and maintain some sort of arms length but civilized relationship with your ex. You owe it to your children to remove blame from the situation and move forward.