If someone else keeps bringing up your past, learn to walk away from them. They obviously have issues with your success or their own failure.
One thing is never feel guilty about your past. It’s all ok. Surround yourself with people who are real to your needs.
We are here to learn; do not be so hard on yourself that you will loose motivation, and not be too light that you will fill yourself with apathy. Do the best you can, and God will meet you half-way.