I used to be a person who would bite the hand that reached out to me; you can unlearn it! :) I started opening my heart to people, and the reception was touching, and it made me want to be even more gentle and kind to people. You get the energy of what you give; if you show kindness to others, people will show kindness to you. I have never mistreated loved ones and never will, but I know what it's like to push them away. It sounds like it was recent for you. I'm sure if you contact your last friend again, you will be received with open arms. It's incredibly difficult to figure out why on earth you would isolate yourself, especially if you want to have connections, so that might be why you're clinging on to explanations. I cannot give you an explanation myself; however, everyone has had a shameful realization that they weren't as kind as they wanted to be and that they would love to go back in time and change their ways, but you cannot hold on to that forever and keep hating yourself. With the knowledge that you have now, focus on the present and how your current actions affect others, positively or negatively.