He was on drugs 'that night' ?
Was he also on drugs for the several days afterwards that he continued to harass her?
Was he also on drugs when he went back and threatened her?
How long has he had this terrible drug problem and is he getting help for it?
He's gone from a really great guy, true pillar of the community - to a drug taking sex manic in the five days you were away? This is what you believe?
I understand if you are desperate to believe him - but if you are able to step back - really? Does what he is claiming seem like the likely explanation?
Either he was on drugs the night he tried to make her have sex with him and for the several days afterwards that he continued to harrass her and when he went to her home to threaten her
Or he was on drugs when he initially tried to make her have sex with him and she's lying about everything else
Or he tried to get someone he felt was a 'safe bet' to sleep with him, it's blown up in his face and he is saying anything and everything he can to get you to believe what is very clearly a great big load of bollocks.
It is your choice whether to stay with him or not. Nobody here can tell you what to do. If you want to stay with him, that's up to you.
But please do so knowing exactly who he is and what he tried to do to that poor woman. Don't pretend that you believe the load of shit he's coming up with.