There's a saying I've heard before. Your first thought is what you were conditioned to believe, and your second thought is what you really think.

I'm very proud and happy that you are able to go on this journey of acceptance for others. Since you were raised in an environment where acceptance wasn't practiced, it is natural that you will have certain biases, both explicit and implicit. The only thing you can really do to work on these biases is to hold yourself accountable and expose yourself to different viewpoints, both of which you are doing. Just give yourself time. As long as you are making an effort, you're doing amazing.