Wow, first I am glad you are still alive. Now to answer your question, did he use you? 20 years is a long time...it is possible there was something real there at some point. however the focus needs to be on the here and now, and it seems like he is not good for you at all. why are you sad, well it is normal to be sad even if the person turns out to be terrible, its not about him, but about the hopes and dreams you had for your life. that is a loss and you are going to feel it.
But what you have to do now is not think about him, or what he tells others, you need to be clear on what you KNOW to be true, he might spin things to look better, but neither he or the people who believe him matter any more. Start on rebuilding yourself. Cut him off, block him and move forward. If you are not sure how to do that, stat with checking out my podcast "From DEVASTATED to Divorced" it is a FREE resource that you can access wherever podcasts are streamed. YOU CAN DO THIS!!