You did the right thing if you don't want to be open to him being a part of your life now. It is so hard not to second guess yourself and even wonder, or at least I do, if his hatefulness and gaslighting is my fault. I have to stay strong and look for a future without someone always making me the guilty party always and blaming me for everything. I find waking in the mornings is the hardest knowing there is no one there with me in the house, but as the day goes on I think about some of the hurtful and hateful things done and said. If you are happy at peace and afraid to get ensnared in a future relationship however platonic, you have to have belief you did the right thing for yourself. Hope that gives some insight.