My (30F) boyfriend (32M) seems to be a pathological liar. I am so lost?

TLDR: My (30F) boyfriend (32M) is an alcoholic, apparently not a reformed childhood criminal (as he led me to believe) but a pathological liar who literally made up an ex-girlfriend only to grieve her passing… Because apparently (his words) he tricked himself into thinking she was real.

Long version:

I (30F) have been dating my boyfriend (32M) for a little over two years now. I’ve known since the beginning he has a problem with alcohol. I then got to know the “reason” behind his excessive drinking (all lies according to his last version), which up until a few weeks ago was that he had been a criminal as a teen. From what he has told me in bits and pieces over these two years (only when so drunk that he has no control over what he is saying and doesn’t remember the next day), apparently he used to be part of a criminal gang. Apparently they were quite dangerous, and he was one of those teens that were being used by criminals to commit crimes for them because of the lenient sentencing for children. He also told me he used to be a “gun for hire” of sorts, who had hurt people and sometimes “unalived” them. He also told me a few months ago (and this was the first time he’d ever cried in front of me), of all the people in his life he has lost: his dog, his dad, his girlfriend, and various friends. His girlfriend, according to what he said, had been just 14 (like him) when she was killed during a shooting match. He literally stood there, crying over how many people that had been dying all around him. He said he cannot online with the emptiness and loneliness, and the shame and guilt over the many people who had to die for his sake.

Well, like I said in the beginning, apparently all lies. Apparently, he was never part of a criminal gang, he never hurt anyone, and his dead ex-girlfriend never even existed! Because what he’s told me now, this time completely sober, is that he used to inflict self-harm. The scars were deep and apparent, and because of that he felt he had to lie about them. So instead of being a sad boy who hurt himself because of depression, he was a bad boy who gained scars as a status symbol and hurt people. When I asked about his ex, since none of that makes sense if it was all a lie, he told me she was a lie as well. He doesn’t remember why he made her up in the first place, only that he’s been telling other people this lie for so long that he’s started to believe in it himself. So, if I am to believe this last version is the truth, he did not lie about her on purpose.

Needless to say, I am slowly but surely losing my sanity. I have been feeling all sorts of emotions. Confusion, guilt (because why the hell am I staying with him, knowing about the (apparently non-existent) ghosts?), sadness, and some fear. Mixed with all of this he told me that I shouldn’t know any more, because some people from his past might find me and try to torture me for information. At a later time he’s confessed that this was unlikely to happen, and that he was just worried I might look at him differently. Oh and another thing that might be relevant, is that the day after I made it clear I cannot be with him because of all this (when I didn’t “know” he was lying), is when he told me he made it all up to hide the truth about his self-inflicted scars.

Like I said, I have been battling with some mixed emotions. I absurdly enough believe him now, about how it was all a lie. But at the same time, how do I not know the first version isn’t true after all, and he is just lying to protect himself or someone else? Or just saying whatever will work to keep me with him? I am no longer mad at him. Now, I am more worried about him. For his psyche. And I feel really sad about the entire situation. I feel really bad for him, and I want so much to help him heal… But at the same time, I honestly don’t know how much more of this I can take. The stress of having this constantly on my mind has been taking its toll on me. Not to mention the fact that I have not been able to talk to anyone. Because, as I saw it, we are not enemies so why ruin his life? Because if I mention the (alleged) “unaliving” to anyone, even a psychologist, I might potentially ruin his life. I know a lot of people are going to judge me for that, but that is why I’ve been battling with these thoughts alone… to then find out it was all a lie.

Like I said, I just want him to heal. But one thing I cannot get over, is the fact that he could stand there and “grieve” a non-existent person. I know nothing about being a pathological liar, so maybe that’s why, but there is some resentment inside of me because of this. I know he genuinely grieves his loved ones. But something about him standing there, showing his raw emotions and true self at last, and then at the same time crying about a made-up story… it rubs me the wrong way. Like, what even are relationships to him if he can grieve the real and the made-up at the same time?

Anyway, this was something of a rant, but I just needed to get it all off me. I’ve had no one but him to talk to. But at least now this should be more “safe”. Since it turns out that he is “just” a liar… Advice and reflections are more than welcome.