Hi, I'd like to help you with your question.
Most likely, if you still have resentment after several years, it means that the feelings you have about what happened to you are still unresolved. Resentment is usually the result of being hurt by someone who you feel wronged you in some way. The pain of the incident stays with you and becomes unresolved if you cannot work through it.
Resentment can also linger if the person has a history of being hurt by others. It is easy to take the pain and hurt from the past and put it all on the current situation. This makes moving on and resolution of the resentment more difficult. In this case, therapy can help the person work through how they feel and rid themselves of the resentment.
I hope this has helped you,