Petey, you have un-finished business to take care of. You need and obviously want to re-connect with your family. Now is your chance. It might be the hardest thing you ever had to do, but with what you have shown us, you can do it. The compassion that you have shown here, and the strength, show that you are equipped to do and say what you have to do and say to make your family believe that you love them and want them in your life. It will require humility, and energy, and right now I am sure that you are low on energy.....but heck, if you can do what you did last week, with all of that work on your property, you can do this.
Do it now, before your rad. treatments slow you down. If you can't bring yourself to speak the words you need to speak, or if you don't have the opportunity, use your beautiful gift of writing. You have a beautiful way of expressing yourself, and with the written word, you can work with your message until it says exactly what you want it to say. Then you can follow it up with contact. And whether or not you get the response you hope for at first, at least you have said what you wanted to say, and you have extended your hand.
If things are as bad as you say, they might not take that hand immediately. Don't stop trying. Write again, never showing any sort of anger, but simply expressing your love for them and your need for them in your life right now.
This project will probably make radiation treatments seem like playtime, so get with the program and don't let us hear you talk about giving up on any of it.
What's the worst that can happen?? That you won't get them back?? Is that worse than what you have now? And what's the best that can happen?? That they DO respond and come back into your life on some level. If they do that, then there is always hope that they will come closer and closer as time goes by.
You can't make things worse by trying, and you might make them better. I'm betting on you. Let them see the old Petey....the one they used to love and probably still do.
Good Luck. XOXOXOXO