Sounds like he was a hazard being that drunk in a public space, especially near a railroad. Sorry this happened to you but well done for saving him and yourself. I think try get some therapy if you can afford it, even if its a session or two. I doubt anything else could come of this.

Even if it did it's clear you did your best to help and that it wasn't intentional. Going to therapy would also work in your favour to show you have been traumatised by the unfortunate incident.

But that shouldn't be the reason you go...

What I meant, but worded it badly, is in situations like this it is always best to apologise and speak to the people involved directly instead of going and talking to everyone else and asking the internet. People can't give you the best advice because they don't really know the person, the best way for you to learn is to speak to people yourself and apologise and ask how to make it up to them.

Personally, I feel some things you can turn to the internet for help with but this is one of the times when it's best to clear the air directly and find out where you stand instead of avoiding it.

Happy to hear everything is okay though

If you feel so bad just apologise without making excuses, don't explain yourself. Just say you are sorry. Stop writing about it on the internet and talking to everyone except her about it and just speak to her.

You didn't really do anything wrong imo. It's just a bad situation. Hopefully she'll be okay and rethink the amount she drinks in future. I don't say this to victim blame her because I don't think what you did counts as sexual assault, but it's not wise to drink so much that you blackout.