You didn't wreck it, but you're going to have to go slow on the alcohol from now on. I'm guessing you're in the UK and this is going to be hard, since pretty much everything is centered around drinking in a way it isn't in the US, but your tolerance for alcohol is going to be radically different from what it was before. I'm ten months out and can get knocked for a loop with two G&Ts. Three months is still pretty early for reintroducing alcohol, talk to your doctor about when you can start drinking again - and obviously your changed drinking tolerance is going to impact decision-making... and that's where the coke comes in. Because you know you shouldn't be doing that with a compromised digestive system and surgical healing.
Talk to your doctor about the recreational drugs too. Or, if you think you're going to hit a judgement wall there, talk to another health counselor.
If it helps at all, there's a significant cultural difference US/UK when it comes to talking about drugs, and I think you accidentally ran into the buzzsaw with your original post. The puritanical streak in the US is considerably wider and more opinionated than in the UK. There are a lot of posts around this forum about how people's social lives have changed now they can't drink much and it's changed the way they experience the bar, so maybe look up some of those to find fellow travelers?