You’ve already started. Letting yourself remember and deciding you want to make changes are the things you needed to do to begin the road to recovery. Now it’s time to get past regret and self-blame and to start doing what you need to do to make things better.
I might be wrong, but I think it would be helpful for you to share what you told me with your mother. It would help her understand your behavior. Further, apologies do matter. Apologize for the ways you have hurt her and ask for her help in moving on. Let her be a mother to you. You could use her support. It’s also important that she understand why you might not be excited about reestablishing contact with the relatives and would give her further reason to think about whether she really wants to reconnect.
Then, please: Find a therapist. Therapy can help you name and deal with your feelings in a positive way. A therapist can offer you both practical advice and important support as you work on turning your life around. If you could have done it on your own, you would have done it already. If therapy isn’t available to you, see if there are services at your college or in your community for young people like yourself. These days, another option is joining an online support group or doing some online therapy.
I applaud your effort to take charge of your life. You can do it. You can make the life you want for yourself. It will be difficult at times but you have already shown that you have what it takes to think hard about yourself and to commit to change.
I wish you well.