Welcome,here you can find plenty of bible smart people to talk to or even make new friends,yeah it's tough thinking on past mistakes or not feeling of value but God can bring you through such dismal times,though as far as forgiving yourself,Gabriel is right,only God and Jesus have the power to forgive any sins you have done,not you,though it's good to have friends that can encourage you to move forward past old strifes,talking about such things can help and to further pry away from the past, walk alongside God and not dwell on the past,true you might not forget it,but healing starts with trying to do better,not simply wishing to do better,for true it is written"blessed are they who mourn for they will be comforted" but if you never get past the time of mourning over event then you can't move forward,just try to leave the past behind you and embrace the blessings God has waiting for you!