All relationships can "go wrong" it's very easy to see a person and how great their other relationships are looking in. You diagnose yourself as the prblem "he's not like this with other ppl so it must be me" that way you have a false sense of control. If you get it wrong then you can get it right somehow. The truth is that it takes 2 ppl in any relationship and he is responsible for this failure. Perhaps even more so in this situation.

I know it is hard to hear because you may feel attached to who he was before and not who he is now, but the best thing you can do is find someone who can really help. What you need is not wrong but he cannot help you with that. Maybe he did but he doesn't seem to now.

I hope you are well. You deserve so much healing.