I don't know what happened in your past JR and it seems to weigh heavily on your heart, I wish I knew but there's things you can do now, don't let your past regrets interfere with your present, future and happiness.
There's a lesson to be learnt in pain and sadness that you won't let chances pass you by again, by the sounds of it you already have because you have accepted responsibility for your actions/inactions and not blaming others, you've accepted the circumstances. Maybe you need to grieve for your regrets with a view to move on and hopefully help you stop revisiting those regrets over and over again.
Don't let those past regrets take over because JR in 10 years time you'll be regretting the fact that those 10 years were spent on regretting the regrets previously. (hope you can follow that and it makes sense)