I have felt as you feel at this moment many times in my life, and am a living testimony of how God's faithfulness is forever. His word says the same. One thing that has helped me is knowing God is not man; He is God. We can't see God how we see others or how we've been treated but instead read of His character, His faithfulness, His love, etc.
Lord, I pray you help this person come to know You as You are in all these areas of needed. Please liberate and deliver this person from all these wrongful feelings for we know that You only bring peace and anything else is not from You. Please help this person be perfected in Your love, for we know that Your love casts out all fears. Help this person grow in Your love and know with a realization that Your love endures forever and is faithful. Help this person come to know You, Lord, for who You are and bring the same realizations to this persons life. In Jesus' name I pray. Amen.