Hi Aniduan,
I would like to add the following comments.
1) If, you find that your past regrets still surface from time to time despite trying not to dwell on them, then perhaps you may do something to feel better.
Sometimes we inadvertently say or do hurtful things to others, and putting in efforts to make amends is appropriate. If possible, you may try to apologize to those whom you may have hurt. Tell them that you regret hurting them and wish that they would be well and put the past behind them. Then, after making proper amends, resolve that it would be your turn to put the past behind you. I hope, in this way, those past regrets would not return to haunt you. It would be psychologically helpful too, not to relive those past regrets.
2) If there is anything you do not understand about Buddhadhamma, feel free to post your queries here or to ask other knowledgeable and helpful Buddhists for their help in understanding. All of this should eventually help you very much.
Hope this helps! :)