Pushing everyone away is usually because , you need space and you can’t always explain it to people!! I understand you must have had tough life and situations that got you to push people no matter what reason it was. Perhaps they got so hurt from it too, you may hold regrets? but if you want them back try to explain the situation to them, if they “truly care” they will try to understand you. Another thing you trying fixing this may help you forgive yourself but first you have to try and put some effort in this because honestly nothing is easy. And nothing lasts forever WE LEARN from out past so get your future to be bright don’t get stuck with your past let it be but you make a better version of yourself.
Unfortunately, sometimes our mental health issues can make it difficult to feel good about ourselves and see our worth through other peoples eyes. When we're at our worst, sometimes pushing everyone away can feel like a mercy on them, even though it's at this time we probably need them the most. But if we are to forgive ourselves for doing this, we first must accept that we are human, and likely afraid. We make mistakes, often in what we think is the name of wanting the best for others, but most this likely reflects how we actually feel about ourselves. We then don't mean ill to others, but to ourselves. Accepting this, and accepting whatever challenges led you to feel this way about yourself with the same warmth and compassion as you'd offer others, can eventually help you understand and forgive yourself for pushing others away.