I recently wrote this letter to my niece who is going through a really hard time, but the principles apply to many. I have shared portions of it in the hopes that it will help others as well.
I know that your situation is really hard to deal with... remember that  are human which means that they make mistakes and do things they shouldn’t. That doesn’t make what they do ok, but you need to forgive them just like God has forgiven the wrong things that you have done. I know it is hard to do, it is something I am still dealing with myself so I understand what you are going through. But I also know that holding on to it and not forgiving them will destroy you. By not forgiving we make ourselves just as bad as those who hurt us. We need to resist the temptation to retaliate in any way because God says that vengeance is His job. Resist the temptation to vindicate yourself, make yourself the victim or seek sympathy from others. All of those things will keep you from being healed. Instead, accept responsibility for what you have done, forgive, love and pray for those who have hurt you, and do your best to be at peace with them.
Titus 3:1 Remind them to be subject to rulers, to authorities, to be obedient, to be ready for every good deed, to malign no one, to be peaceable, gentle, showing every consideration for all men. For we also once were foolish ourselves, disobedient, deceived, enslaved to various lusts and pleasures, spending our life in malice and envy, hateful, hating one another. But when the kindness of God our Savior and His love for mankind appeared, 5 He saved us, not on the basis of deeds which we have done in righteousness, but according to His mercy, by the washing of regeneration and renewing by the Holy Spirit, 6 whom He poured out upon us richly through Jesus Christ our Savior,so that being justified by His grace we would be made heirs according to the hope of eternal life. This is a trustworthy statement; and concerning these things I want you to speak confidently, so that those who have believed God will be careful to engage in good deeds. These things are good and profitable for men. (NASB)
No matter what any one does to us, we need to be kind and loving to them. It is really hard to do, but it is easier if we surrender everything to God and trust Him. He will give us the strength and love to love others regardless of how they treat us. Without Him we can’t even try.
Take this opportunity of a new beginning to focus your life on God. Pursue Him with a passion. It will be slow going at first, but if you keep at it, it will become easier and you will grow to love it. That is the only thing that will keep you on the right course. There are many other things in this world that may take away the pain for the time, but they will destroy you in the end. Follow God. He doesn’t make His rules to keep you from being happy. They truly are the best way to live and the only way to keep yourself from being destroyed. He made them because He loves you and He wants you to know the best way to live your life. He made your life and He knew what would happen, so He knows what is best for you to do. Trust in Him. He loves you more deeply than any earthly father ever could. He doesn’t want you to suffer, but He won’t stop you from making the choices you do either. The only way for Him to have influence in your life, to help you, is for you to turn to Him and surrender everything to Him. Please, don’t ruin your life by being bitter, manipulative or wallowing in self pity. When you are tempted to do that, stop yourself and pray, think only about the good things of God. When you remember bad things that have happened, force yourself to think of something that God has blessed you with. When you are tempted to talk bad about someone that has hurt you, force yourself to think of something good about that person. Stay grounded in the truth of what God says about you and others. Don’t let the words or actions of others bring you down or make you hate or resent them. It will take a lot of hard work, but it will change your life for the better. God can make this situation work out for your benefit if you will trust Him with it and act as He wants you to. If you don’t, it will continue to get worse. The sooner you deal with it, the better and easier it will be.
There is wonderful joy ahead, even though you have to endure many trials for a little while. These trials will show that your faith is genuine. It is being tested as fire tests and purifies gold - though your faith is far more precious than mere gold. So when your faith remains strong through many trials, it will bring you much praise and glory and honor on the day when Jesus Christ is revealed to the whole world. . . . The reward for trusting him will be the salvation of your souls. 1 Peter 1:6-7, 9
New Living Translation (NLT)