I'm still confused about which part of the past few episodes have been real and which have been hallucinations! Can someone please explain to me?

Here's what happened: first of all this time House was NOT hallucinating, he was having delusions, which is a bit different. His delusions started the very moment Cuddy told him "Screw you" in UMS. Everything that happened that night and the morning after, meaning the detox, her helping him and comforting him, her admitting liking him for 20 years, him admitting he always wants to KISS her and then them having sex, was a delusion. BUT, after House wakes up, everything is real, except for the fact that he sees lipstick on his face and for the lipstick itself, which was in fact his bottle of pills. Everything we saw in the finale was real, House's feelings, the dialogs, the conflicts, the patients, Wilson advice, his argues with Cuddy, everything was real, except for the lipstick... and Amber and Kutner of course. When Cuddy told him that she was angry at him for insulting her and she left that night, House started realizing what had really happened and... Du know the rest! I hope this helps you.

Everything in UMS after House insults Cuddy is a hallucination. Everything around House in BSN is real except he is hallucinating that the Vicodin bottle is lipstick and he has the delusion that Cuddy is just overacting about the sex the night before and is trying to hide her deep Liebe for him. (half of that really isn't a delusion, she is trying to hide her deep Liebe from him just not in the context he thinks.)