Hello, I'd like to help you with your question.
It is understandable that you feel lost, upset or sad about your now ex husband telling you he was gay while you were married. When you are married, you make assumptions that your partner is sexually compatable with you and very few people question this in their marriage. We may think that affairs are possible (though we hope not) but not a change in orientation. So suddenly hearing that your husband is no longer interested in women can be a shock.
However you feel about this news, it is ok to tell your ex husband that you feel that way. It is important that you have a chance to express yourself and have your side heard. Hopefully, your ex husband is willing to be understanding and supportive. He not only told you that he was gay but he also turned on the family and was cruel to you and your children. That is a lot to handle so he should expect you to react in some way.
Leaving the marriage then turning to drugs is very traumatic. To expect you to accept him back as if it is all normal, even if your children do (and you were good to present your ex husband in a good light, despite his choices), is expecting a lot. And how you are feeling now is a natural reaction to what you have been through.
It is important that you and your ex decide how you want to handle your relationship from here on out. You need support to help you sort out how you feel and how you can relate to your ex in such a way that you feel safe and ok about it.
It is a good idea to see a counselor but I understand if you feel you do not want to at this point. It does make it more difficult to cope with your feelings without support, so try to find support through friends and family, if possible. Also consider self help. There are numerous forums (which helps because you are anonymous) and other on line resources, including counseling. Here are some resources to help you:
Putting Children First: Proven Parenting Strategies for Helping Children Thrive Through Divorce by JoAnne L. Pedro-Carroll
The Journey from Abandonment to Healing: Turn the End of a Relationship into the Beginning of a New Life by XXXXX XXXXX
Also, if you attend church, talk to your pastor. A pastor can offer support so you don't feel so alone.
Be sure to take care of yourself in this situation. There is a tendency to push aside how we feel because it is so painful and hard to cope. But being sure you are ok and allowing yourself to express your feelings will help you in the long run to come out of this feeling better.
I hope this has helped you,